History of Vietnam

Vietnam is a multi-ethnic country on Mainland Southeast Asia and has great ethnolinguistic diversity. Vietnam's demography consists 54 different ethnicities belong to five major ethnolinguistic families: Austronesian, Austroasiatic, Hmong-Mien, Kra-Dai, Sino-Tibetan. Among 54 groups, the majority ethnic group is the Austroasiatic-speaking Kinh alone comprising 85.32% of total population. The rest is made up of 53 other ethnic groups. Vietnam's ethnic mosaic is contributed by the peopling process in which the various people came and settled on territory, that constitutes the modern state of Vietnam in many stages, often separated by thousands of years, totally lasted for tens of thousand years. It is evident that entire Vietnam's history is embroidered polyethnic.^[1]

Holocene Vietnam began during the Late Pleistocene period. Early anatomically modern human settlement in Mainland Southeast Asia dated back to 65 kya (65,000 years ago) to 10,5 kya. They were probably the foremost hunter-gatherers whom called the Hoabinhians, a large group that gradually settled across Southeast Asia, probably akin to modern-day Munda people (Mundari-speaking people) and Malaysian Austroasiatics.^[2]

While the true original inhabitants of Vietnam were the Hoabinhians, they had of course been replaced and absorbed by the East Eurasian-looking populace and the expansion of preliminary Austroasiatic and Austronesian languages, although linguistic is not totally interrelated with genetic. And later on that trend is continued with the expansion of Tibeto-Burman and Kra-Dai speaking population, and the latest Hmong-Mien speaking communities. The results are all of modern ethnic groups of Vietnam possess various ratios of genetic admixture between the Eastern Eurasian and Hoabinhian groups.^[1]

The Cham people, who for over one thousand years settled in, controlled and civilized present-day central and southern coastal Vietnam from around the 2nd century CE are of Austronesian origin. The southernmost sector of modern Vietnam, the Mekong Delta and its surroundings was until the 18th century an integral part, yet of shifting significance of the Austroasiatic Proto-Khmer – and Khmer principalities, like Funan, Chenla, the Khmer Empire and the Khmer kingdom.^[3]

Situated on the southeast edge of monsoon Asia, much of ancient Vietnam enjoyed a combination of high rainfall, humidity, heat, favorable winds, and fertile soil. These natural sources combined to generate an unusually prolific growth of rice and other plants and wildlife. This region's agricultural villages held well over 90 percent of the population. The high volume of rainy season water required villagers to concentrate their labor in managing floods, transplanting rice, and harvesting. These activities produced a cohesive village life with a religion in which one of the core values was the desire to live in harmony with nature and with other people. The way of life, centered in harmony, featured many enjoyable aspects that the people held beloved. Example included people not needing many material things, enjoyment of music and poetry, and living in harmony with nature.^[4]

Fishing and hunting supplemented the main rice crop. Arrowheads and spears were dipped in poison to kill larger animals such as elephants. Betel nuts were widely chewed and the lower classes rarely wore clothing more substantial than a loincloth. Every spring, a fertility festival was held which featured huge parties and sexual abandon. Since around 2000 BCE, stone hand tools and weapons improved extraordinarily in both quantity and variety. After this, Vietnam later became part of the Maritime Jade Road, which existed for 3,000 years between 2000 BCE to 1000 CE.^[5] Pottery reached a higher level of technique and decoration style. The early farming multilinguistic societies in Vietnam were mainly wet rice Oryza cultivators, which became the main staple of their diet. During the later stage of the first half of the 2nd millennium BCE, the first appearance of bronze tools took place despite these tools still being rare. By about 1000 BCE, bronze replaced stone for about 40 percent of edged tools and weapons, rising to about 60 percent. Here, there were not only bronze weapons, axes, and personal ornaments, but also sickles and other agriculture tools. Toward the closure of the Bronze Age, bronze accounts for more than 90 percent of tools and weapons, and there are exceptionally extravagant graves – the burial places of powerful chieftains – containing some hundreds of ritual and personal bronze artifacts such as musical instruments, bucket-shaped ladles, and ornament daggers. After 1000 BCE, the ancient peoples of Vietnam became skilled agriculturalists as they grew rice and kept buffaloes and pigs. They were also skilled fishermen and bold sailors, whose long dug-out canoes traversed the eastern sea.

The Phùng Nguyên culture of Vietnam (c. 2,000 – 1,500 BCE) is a name given to a culture of the Bronze Age in Vietnam which takes its name from an archeological site in Phùng Nguyên, 18 km (11 mi) east of Việt Trì discovered in 1958.^[6] It was during this period that rice cultivation was introduced into the Red River region from southern China.^[7] The first Phùng Nguyên culture excavation was in 1959, known as Co Nhue. The sites of Phùng Nguyên culture are usually several meters higher than the surrounding terrain and near rivers or streams.^[8]

The Sa Huỳnh culture was a culture in modern-day central and southern Vietnam that flourished between 1000 BCE and 200 CE.^[9] Archaeological sites from the culture have been discovered from the Mekong Delta to Quảng Bình province in central Vietnam. The Sa Huynh people were most likely the predecessors of the Cham people, an Austronesian-speaking people and the founders of the kingdom of Champa.^[10]

The Sa Huỳnh culture showed evidence of an extensive trade network that existed between 500 BCE to CE 1500, known as the Sa Huynh-Kalanay Interaction Sphere (named after the Sa Huỳnh culture and the Kalanay Cave of Masbate, Philippines). It was mainly between Sa Huỳnh and the Philippines, but also extended into archaeological sites in Taiwan, Southern Thailand, and northeastern Borneo. It is characterized by shared red-slipped pottery traditions, as well as double-headed and penannular ornaments known as lingling-o made from materials like green jade (sourced from Taiwan), green mica (from Mindoro), black nephrite (from Hà Tĩnh) and clay (from Vietnam and the Northern Philippines).^[11] Sa Huynh also produced beads made from glass, carnelian, agate, olivine, zircon, gold and garnet; most of whom use materials that are also imported. Han dynasty-style bronze mirrors were also found in Sa Huynh sites.^[11]

The Baiyue (Hundred Yue, or simply Yue), were various ethnic groups who inhabited the regions of Southern China and Northern Vietnam during the 1st millennium BCE and 1st millennium CE.^[19] They were known for their short hair, body tattoos, fine swords, and naval prowess. During the Warring States period, the word "Yue" referred to the State of Yue in Zhejiang. The later kingdoms of Minyue in Fujian and Nanyue in Guangdong were both considered Yue states. Meacham notes that, during the Zhou and Han dynasties, the Yue lived in a vast territory from Jiangsu to Yunnan,^[20] while Barlow indicates that the Luoyue occupied the southwest Guangxi and northern Vietnam.^[21] The Book of Han describes the various Yue tribes and peoples can be found from the regions of Kuaiji to Jiaozhi.^[22] The Yue tribes were gradually displaced or assimilated into Chinese culture as the Han empire expanded into what is now Southern China and Northern Vietnam.^{[23 ]}

The Red River valley formed a natural geographic and economic unit, bounded to the north and west by mountains and jungles, to the east by the sea and to the south by the Red River Delta.^[12] The need to have a single authority to prevent floods of the Red River, to cooperate in constructing hydraulic systems, trade exchange, and to repel invaders, led to the creation of the first legendary Vietnamese states approximately 2879 BCE. While in the later times, ongoing research from archaeologists has suggested that the Vietnamese Đông Sơn culture were traceable back to Northern Vietnam, Guangxi and Laos around 700 BCE.^[13]

Vietnamese historians attribute the culture to the states of Văn Lang and Âu Lạc. Its influence spread to other parts of Southeast Asia, including Maritime Southeast Asia, from about 1000 BCE to 1 BCE. The Dong Son people were skilled at cultivating rice, keeping water buffalos and pigs, fishing and sailing in long dugout canoes. They also were skilled bronze casters, which is evidenced by the Dong Son drum found widely throughout northern Vietnam and South China.^[14] To the south of the Dong Son culture was the Sa Huỳnh culture of the proto-Chams.

The Lạc Việt or Luoyue were a conglomeration of multilinguistic, specifically Kra-Dai and Austroasiatic, Yue tribal peoples that inhabited ancient northern Vietnam, and, particularly the ancient Red River Delta,^[24] from ca. 700 BCE to 100 CE, during the last stage of Neolithic Southeast Asia and the beginning of classical antiquity period. From the archaeological perspectives, they were known as the Dongsonian. The Lac Viet was known for casting large Heger Type I bronze drums, cultivating paddy rice, and constructing dikes. The Lạc Việt who owned the Bronze Age Đông Sơn culture, which centered at the Red River Delta (now in northern Vietnam, in mainland Southeast Asia),^[25] are hypothesized to be the ancestors of the modern Kinh Vietnamese.^[26] Another population of Luoyue, who inhabited the Zuo river's valley (now in modern Southern China), are believed to be the ancestors of the modern Zhuang people;^[27] additionally, Luoyue in southern China are believed to be ancestors of Hlai people.^[28]

According to a Vietnamese legend which first appeared in the 14th century book Lĩnh nam chích quái, the tribal chief Lộc Tục proclaimed himself as Kinh Dương Vương and founded the state of Xích Quỷ, that marks the beginning of the Hồng Bàng dynastic period. However, modern Vietnamese historians assume, that statehood was only developed in the Red River Delta by the second half of 1st millennium BCE. Kinh Dương Vương was succeeded by Sùng Lãm. The next royal dynasty produced 18 monarchs, known as the Hùng Kings. Starting from the third Hùng dynasty, the kingdom was renamed Văn Lang, and the capital was set up at Phong Châu (in modern Việt Trì, Phú Thọ) at the juncture of three rivers where the Red River Delta begins from the foot of the mountains.^[15]

The administrative system includes offices like military chief (lạc tướng), paladin (lạc hầu) and mandarin (bố chính).^[16] Great numbers of metal weapons and tools excavated at various Phung Nguyen culture sites in northern Indochina are associated with the beginning of the Copper Age in Southeast Asia.^[17] Furthermore, the beginning of the Bronze Age has been verified for around 500 BCE at Đông Sơn. Vietnamese historians usually attribute the Đông Sơn culture with the kingdoms of Văn Lang, Âu Lạc, and the Hồng Bàng dynasty.

The local Lạc Việt community had developed a highly sophisticated industry of quality bronze production, processing and the manufacturing of tools, weapons and exquisite Bronze drums. Certainly of symbolic value they were intended to be used for religious or ceremonial purposes. The craftsmen of these objects required refined skills in melting techniques, in the Lost-wax casting technique and acquired master skills of composition and execution for the elaborate engravings.^[18]

By the 3rd century BCE, another Viet group, the Âu Việt, emigrated from present-day southern China to the Hồng River delta and mixed with the indigenous Văn Lang population. In 257 BCE, a new kingdom, Âu Lạc, emerged as the union of the Âu Việt and the Lạc Việt, with Thục Phán proclaiming himself "An Dương Vương" ("King An Dương"). Some modern Vietnamese believe that Thục Phán came upon the Âu Việt territory (modern-day northernmost Vietnam, western Guangdong, and southern Guangxi province, with its capital in what is today Cao Bằng Province).^[29]

After assembling an army, he defeated and overthrew the eighteenth dynasty of the Hùng kings, around 258 BCE. He then renamed his newly acquired state from Văn Lang to Âu Lạc and established the new capital at Phong Khê in the present-day Phú Thọ town in northern Vietnam, where he tried to build the Cổ Loa Citadel (Cổ Loa Thành), the spiral fortress approximately ten miles north of that new capital. Cổ Loa, the largest prehistoric moated urban settlement in Southeast Asia,^[30] was the first political hub of Vietnamese civilization in the pre-Sinitic era, encompassing 600 hectares (1,500 acres), and requiring as many as 2 million cubic meters of material. However, records showed that espionage resulted in the downfall of An Dương Vương.

After Qin Shi Huang conquered the six other Chinese kingdoms of Han, Zhao, Wei, Chu, Yan, and Qi, he turned his attention to the Xiongnu tribes of the north and west and the Hundred Yue peoples of what is now southern China. As trade was an important source of wealth for the Baiyue peoples of coastal southern China, the region south of the Yangtze River attracted the attention of Emperor Qin Shi Huang. Lured by its temperate climate, fertile fields, maritime trade routes, relative security from warring factions to the west and northwest, and access to luxury tropical products from Southeast Asia, the emperor sent armies to conquer the Yue kingdoms in 221 BCE.^[31] Around 218 BCE, the First Emperor dispatched General Tu Sui with an army of 500,000 Qin soldiers to divide into five companies and attack the Hundred Yue tribes of the Lingnan region. Military expeditions against the region were dispatched between 221 and 214 BCE.^[32] It would take five successive military excursions before the Qin finally defeated the Yue in 214 BCE.^[33]

Following the collapse of the Qin dynasty, Zhao Tuo took control of Guangzhou and extended his territory south of the Red River as one of the primary targets of the Qin dynasty was to secure important coastal seaports for trade.^[34] The First Emperor died in 210 BCE, and his son Zhao Huhai became the Second Emperor of Qin. In 206 BCE the Qin dynasty ceased to exist, and the Yue peoples of Guilin and Xiang were largely independent once more. In 204 BCE, Zhao Tuo founded the Kingdom of Nanyue, with Panyu as capital, and declared himself the Martial King of Nanyue and divided his empire into seven provinces, which were administered by a mix of Han Chinese and Yue feudal lords.^[35]

Liu Bang, after years of war with his rivals, established the Han dynasty and reunified Central China in 202 BCE. In 196 BCE, Liu Bang, now Emperor Gaozu, sent Lu Jia to Nanyue in hopes of obtaining Zhao Tuo's allegiance. After arriving, Lu met with Zhao Tuo and is said to have found him dressed in Yue clothing and being greeted after their customs, which enraged him. A long exchange ensued,^[36] wherein Lu is said to have admonished Zhao Tuo, pointing out that he was Chinese, not Yue, and should have maintained the dress and decorum of the Chinese and not have forgotten the traditions of his ancestors. Lu lauded the strength of the Han court and warned against a kingdom as small as Nanyue daring to oppose it. He further threatened to kill Zhao's kinsmen in China proper and destroying their ancestral graveyards, as well as coercing the Yue into deposing Zhao himself. Following the threat, Zhao Tuo then decided to receive Emperor Gaozu's seal and submit to Han authority. Trade relations were established at the border between Nanyue and the Han kingdom of Changsha. Although formally a Han subject state, Nanyue seems to have retained a large measure of de facto autonomy.

The kingdom of Âu Lạc laid south of Nanyue in the early years of Nanyue's existence, with Âu Lạc located primarily in the Red River delta area, and Nanyue encompassing Nanhai, Guilin, and Xiang Commanderies. During the time when Nanyue and Âu Lạc co-existed, Âu Lạc acknowledged Nanyue's suzerainty, especially because of their mutual anti-Han sentiment. Zhao Tuo built up and reinforced his army, fearing an attack by the Han. However, when relations between the Han and Nanyue improved, in 179 BCE, Zhao Tuo defeated King An Dương Vương and annexed Âu Lạc.^[37]

In 111 BCE, the Han dynasty conquered Nanyue during its expansion southward and incorporated what is now northern Vietnam, together with much of modern Guangdong and Guangxi, into the expanding Han empire.^[38] During the next several hundred years of Chinese rule, sinicization of the newly conquered Nanyue was brought about by a combination of Han imperial military power, regular settlement and an influx of Han Chinese refugees, officers and garrisons, merchants, scholars, bureaucrats, fugitives, and prisoners of war.^[39] At the same time, Chinese officials were interested in exploiting the region's natural resources and trade potential. In addition, Han Chinese officials seized fertile land conquered from Vietnamese nobles for newly settled Han Chinese immigrants.^[40] Han rule and government administration brought new influences to the indigenous Vietnamese and Vietnam as a Chinese province operated as a frontier outpost of the Han Empire.^[41] The Han dynasty was desperate to extend their control over the fertile Red River Delta, in part as the geographical terrain served as a convenient supply point and trading post for Han ships engaged in the growing maritime trade with various South and Southeast Asian Kingdoms and the Roman Empire.^[42] The Han dynasty relied heavily on trade with the Nanyue who produced unique items such as: bronze and pottery incense burners, ivory, and rhinoceros horns. The Han dynasty took advantage of the Yue people’s goods and used them in their maritime trade network that extended from Lingnan through Yunnan to Burma and India.^[43]

During the first century of Chinese rule, Vietnam was governed leniently and indirectly with no immediate change in indigenous policies. Initially, indigenous Lac Viet people were governed at the local level but with indigenous Vietnamese local officials being replaced with newly settled Han Chinese officials.^[44] Han imperial bureaucrats generally pursued a policy of peaceful relations with the indigenous population, focusing their administrative roles in the prefectural headquarters and garrisons, and maintaining secure river routes for trade.^[45] By the first century CE, however, the Han dynasty intensified its efforts to assimilate its new territories by raising taxes and instituting marriage and land inheritance reforms aimed at turning Vietnam into a patriarchal society more amenable to political authority.^[46] The native Luo chief paid heavy tributes and imperial taxes to the Han mandarins to maintain the local administration and the military.^[44] The Chinese vigorously tried to assimilate the Vietnamese either through forced signification or through brute Chinese political domination.^[41] The Han dynasty sought to assimilate the Vietnamese as the Chinese wanted to maintain a unified cohesive empire through a "civilizing mission" as the Chinese regarded the Vietnamese as uncultured and backward barbarians with the Chinese regarding their "Celestial Empire" as the supreme centre of the universe.^[40] Under Chinese rule, Han dynasty officials imposed Chinese culture, including Taoism and Confucianism, its imperial examination system, and mandarin bureaucracy.^[47]

Though the Vietnamese incorporated advanced and technical elements they thought would be beneficial to themselves, the general unwillingness to be dominated by outsiders, the desire to maintain political autonomy and the drive to regain Vietnamese independence signified Vietnamese resistance and hostility to Chinese aggression, political domination and imperialism on Vietnamese society.^[48] Han Chinese bureaucrats sought to impose Chinese high culture onto the indigenous Vietnamese including bureaucratic Legalist techniques and Confucian ethics, education, art, literature, and language.^[49] The conquered and subjugated Vietnamese had to adopt the Chinese writing system, Confucianism, and veneration of the Chinese emperor to the detriment of their native spoken language, culture, ethnicity, and national identity.^[41]

The First Era of Northern Domination refers to the period of Vietnamese history during which present-day northern Vietnam was under the rule of the Han dynasty and the Xin dynasty. It is considered the first of four periods of Chinese rule over Vietnam, the first three of which were almost continuous and referred to as Bắc thuộc ("Northern Domination").

One prominent group of ancient people in Northern Vietnam (Jiaozhi, Tonkin, Red River Delta region) during the Han dynasty's rule over Vietnam was called the Lac Viet or the Luòyuè in Chinese annals.^[50] The Luoyue had been indigenous to the region. They practiced non-Chinese tribal ways and slash-and-burn agriculture.^[51] According to French sinologist Georges Maspero, some Chinese immigrants arrived and settled along the Red River during the usurpation of Wang Mang (9–25) and the early Eastern Han, while two Han governors of Jiaozhi Xi Guang (?-30 CE) and Ren Yan, with support from Chinese scholar-immigrants, conducted the first "sinicization" on the local tribes by introducing Chinese-style marriage, opening the first Chinese schools, and introducing Chinese philosophies, therefore provoking cultural conflict.^[52] American philologist Stephen O'Harrow indicates that the introduction of Chinese-style marriage customs might have come in the interest of transferring land rights to Chinese immigrants in the area, replacing the matrilineal tradition of the area.^[53]

The Trưng sisters were daughters of a wealthy aristocratic family of Lac ethnicity.^[54] Their father had been a Lac lord in Mê Linh district (modern-day Mê Linh District, Hanoi). Trưng Trắc (Zheng Ce)'s husband was Thi Sách (Shi Suo), was also the Lac lord of Chu Diên (modern-day Khoái Châu District, Hưng Yên Province).^[55] Su Ding (governor of Jiaozhi 37–40), the Chinese governor of Jiaozhi province at the time, is remembered by his cruelty and tyranny.^[56] According to Hou Hanshu, Thi Sách was "of a fierce temperament". Trưng Trắc, who was likewise described as "possessing mettle and courage", fearlessly stirred her husband to action. As a result, Su Ding attempted to restrain Thi Sách with laws, literally beheading him without trial.^[57] Trưng Trắc became the central figure in mobilizing the Lac lords against the Chinese.^[58]

In March of 40 CE, Trưng Trắc and her younger sister Trưng Nhị, led the Lac Viet people to rise up in rebellion against the Han.^[59] The Hou Han Shu recorded that Trưng Trắc launched the rebellion in avenge the killing of her dissent husband.^[55] Other sources indicate that Trưng Trắc's movement towards rebellion was influenced by the loss of land intended for her inheritance due to the replacement of traditional matrilineal customs.^[53] It began at the Red River Delta, but soon spread to other Lac tribes and non-Han people from an area stretching from Hepu to Rinan.^[54] Chinese settlements were overrun, and Su Ting fled.^[58] The uprising gained the support of about sixty-five towns and settlements.^[60] Trưng Trắc was proclaimed as the queen.^[59] Even though she gained control over the countryside, she was not able to capture the fortified towns.

The Han government (situated in Luoyang) responded rather slowly to the emerging situation. In May or June of 42 CE, Emperor Guangwu gave the orders to initiate a military campaign. The strategic importance of Jiaozhi is underscored by the fact that the Han sent their most trusted generals, Ma Yuan and Duan Zhi to suppress the rebellion. Ma Yuan and his staff began mobilizing a Han army in southern China. It consisted 20,000 regulars and 12,000 regional auxiliaries. From Guangdong, Ma Yuan dispatched a fleet of supply ships along the coast.^[59]

In the spring of 42, the imperial army reached high ground at Lãng Bạc, in the Tiên Du mountains of what is now Bắc Ninh. Yuan's forces battled the Trưng sisters, beheaded several thousand of Trưng Trắc’s partisans, while more than ten thousand surrendered to him.^[61] The Chinese general pushed on to victory. Yuan pursued Trưng Trắc and her retainers to Jinxi Tản Viên, where her ancestral estates were located; and defeated them several times. Increasingly isolated and cut off from supplies, the two women were unable to sustain their last stand and the Chinese captured both sisters in early 43.^[62] The rebellion was brought under control by April or May. Ma Yuan decapitated Trưng Trắc and Trưng Nhị,^[59] and sent their heads to the Han court at Luoyang.^[61] By the end of 43 CE, the Han army had taken full control over the region by defeating the last pockets of resistance.^[59]

The Second Era of Northern Domination refers to the second period of Chinese rule in Vietnamese history, from the 1st century to 6th century CE, during which present-day northern Vietnam (Jiaozhi) was governed by various Chinese dynasties. This period began when the Han dynasty reconquered Giao Chỉ (Jiaozhi) from the Trưng Sisters and ended in 544 CE when Lý Bí revolted against the Liang dynasty and established the Early Lý dynasty. This period lasted about 500 years.

Learning a lesson from the Trưng revolt, the Han and other successful Chinese dynasties took measures to eliminate the power of the Vietnamese nobles.^[63] The Vietnamese elites were educated in Chinese culture and politics. A Giao Chỉ prefect, Shi Xie, ruled Vietnam as an autonomous warlord for forty years and was posthumously deified by later Vietnamese monarchs.^[64] Shi Xie pledged loyalty to Eastern Wu of the Three Kingdoms era of China. The Eastern Wu was a formative period in Vietnamese history. Nearly 200 years passed before the Vietnamese attempted another revolt.

In the early first century CE, on the lower Mekong, the first Indianized kingdom of Southeast Asia which the Chinese called them Funan emerged and became the great economic power in the region, its prime city Óc Eo attracted merchants and craftmen from China, India, and even Rome. Funan is said to be the first Khmer state, or Austronesian, or multiethnic. Though treated by Chinese historians as a single unified empire, according to some modern scholars Funan may have been a collection of city-states that sometimes warred with one another and at other times constituted a political unity.^[65]

The ethnic and linguistic origins of the Funanese people have consequently been subject to scholarly debate, and no firm conclusions can be drawn based on the evidence available. The Funanese may have been Cham or from another Austronesian group, or they may have been Khmer or from another Austroasiatic group. It is possible that they are the ancestors of those indigenous people dwelling in the southern part of Vietnam today who refer themselves as "Khmer" or "Khmer Krom." The Khmer term "krom" means "below" or "lower part of" and is used to refer to territory that was later colonized by Vietnamese immigrants and taken up into the modern state of Vietnam.^[66] While no conclusive study to determine whether Funan's ethnolinguistic components were Austronesian or Austroasiatic, there is dispute among scholars. According to the majority of Vietnamese academics, for example, Mac Duong, stipulates that "Funan's core population certainly were the Austronesians, not Khmer;" the fall of Funan and the rise of Zhenla from the north in the 6th century indicate "the arrival of the Khmer to the Mekong Delta." That thesis received support from D. G. E. Hall.^[67] Recent archaeological research lends weight to the conclusion that Funan was a Mon-Khmer polity.^[68] In his Funan review, Michael Vickery expresses himself a strong supporter of Funan's Khmer predominance theory.

In 192 CE, in present-day Central Vietnam, there was a successful revolt of Cham nations. Chinese dynasties called it Lin-Yi. It later became a powerful kingdom, Champa, stretching from Quảng Bình to Phan Thiết (Bình Thuận). The Cham developed the first native writing system in Southeast Asia, oldest surviving literature of any Southeast Asian language, leading Buddhist, Hindu, and cultural expertise in the region.^[69]

Kingdom of Lâm Ấp

Lâm Ấp was a kingdom located in central Vietnam that existed from around 192 CE to 629 CE in what is today central Vietnam, and was one of the earliest recorded Champa kingdoms. The name Linyi however had been employed by official Chinese histories from 192 to even 758 CE to describe a particular early Champa kingdom located north of the Hải Vân Pass. The ruins of its capital, the ancient city of Kandapurpura is now located in Long Tho Hill, 3 kilometers to the west of the city of Huế.

Kingdom of Xitu

Xitu was the Chinese designation for a historical region or a Chamic polity or kingdom that was first mentioned in the mid of fifth century CE, is believed to be one of the predecessors of Champa Kingdom. It has been proposed to be located in the Thu Bồn River Valley, present-day Quảng Nam Province, Central Vietnam.

Kingdom of Quduqian

Quduqian was the Chinese designation for an ancient kingdom, chiefdom, or a polity that perhaps located around Binh Dinh province, Central Vietnam, then became part of Champa Kingdoms.

Champa was a collection of independent Cham polities that extended across the coast of what is present-day central and southern Vietnam from approximately the 2nd century CE until 1832. According to earliest historical references found in ancient sources, the first Cham polities were established around the 2nd to 3rd centuries CE, in the wake of Khu Liên's rebellion against the rule of China's Eastern Han dynasty, and lasted until when the final remaining principality of Champa was annexed by Emperor Minh Mạng of the Vietnamese Nguyễn dynasty as part of the expansionist Nam tiến policy.^[73] The kingdom was known variously as Nagaracampa, Champa in modern Cham, and Châmpa in the Khmer inscriptions, Chiêm Thành in Vietnamese and Zhànchéng in Chinese records.^[74]

Early Champa evolved from the seafaring Austronesian Chamic Sa Huỳnh culture off the coast of modern-day Vietnam. Its emergence in the late 2nd century CE exemplifies early Southeast Asian statecraft at a crucial stage of the making of Southeast Asia. The peoples of Champa maintained a system of lucrative trade networks across the region, connecting the Indian Ocean and Eastern Asia, until the 17th century. In Champa, historians also witness the first native Southeast Asian literature being written down in native language around c. 350 CE, predating first Khmer, Mon, Malay texts by centuries.^[75]

The Chams of modern Vietnam and Cambodia are the major remnants of this former kingdom. They speak Chamic languages, a subfamily of Malayo-Polynesian closely related to the Malayic and Bali–Sasak languages that is spoken throughout maritime Southeast Asia. Although Cham culture is usually intertwined with the broader culture of Champa, the kingdom had a multiethnic population, which consisted of Austronesian Chamic-speaking peoples that made up the majority of its demographics. The people who used to inhabit the region are the present-day Chamic-speaking Cham, Rade and Jarai peoples in South and Central Vietnam and Cambodia; the Acehnese from Northern Sumatra, Indonesia, along with elements of Austroasiatic Bahnaric and Katuic-speaking peoples in Central Vietnam.^[76]

Champa was preceded in the region by a kingdom called Lâm Ấp, or Linyi, that was in existence since 192 CE; although the historical relationship between Linyi and Champa is not clear. Champa reached its apogee in the 9th and 10th centuries CE. Thereafter, it began a gradual decline under pressure from Đại Việt, the Vietnamese polity centered in the region of modern Hanoi. In 1832, the Vietnamese emperor Minh Mạng annexed the remaining Cham territories.

Hinduism, adopted through conflicts and conquest of territory from neighboring Funan in the 4th century CE, shaped the art and culture of the Cham Kingdom for centuries, as testified by the many Cham Hindu statues and red brick temples that dotted the landscape in Cham lands. Mỹ Sơn, a former religious center, and Hội An, one of Champa's main port cities, are now World Heritage Sites. Today, many Cham people adhere to Islam, a conversion which began in the 10th century, with the ruling dynasty having fully adopted the faith by the 17th century; they are called the Bani (Ni tục, from Arabic: Bani). There are, however, the Bacam (Bacham, Chiêm tục) who still retain and preserve their Hindu faith, rituals, and festivals. The Bacam is one of only two surviving non-Indic indigenous Hindu peoples in the world, with a culture dating back thousands of years. The other being the Balinese Hindus of the Balinese of Indonesia.^[73]

Lady Triệu was a warrior in 3rd century Vietnam who managed, for a time, to resist the rule of the Chinese Eastern Wu dynasty. She is also called Triệu Thị Trinh, although her actual given name is unknown. She is quoted as saying, "I'd like to ride storms, kill orcas in the open sea, drive out the aggressors, reconquer the country, undo the ties of serfdom, and never bend my back to be the concubine of whatever man."^[70] The uprising of Lady Triệu is usually depicted in modern Vietnamese National History as one of many chapters constituting a "long national independence struggle to end foreign domination."^[71]

The sixth century was an important stage in the Vietnamese political evolution toward independence. During this period, the Vietnamese aristocracy, while retaining Chinese political and cultural forms, grew increasingly independent of China. In the period between the beginning of the Chinese Age of Fragmentation and the end of the Tang dynasty, several revolts against Chinese rule took place. In 543, Lý Bí and his brother Lý Thiên Bảo revolted against the Chinese Liang dynasty and briefly ruled an independent Van Xuan kingdom for almost half a century, from 544 to 602, before Sui China reconquered the kingdom.^[72]

The Third Era of Northern Domination refers to the third period of Chinese rule in Vietnamese history. The era starts from the end of the Early Lý dynasty in 602 to the rise of the local Khúc family and other Viet warlords in the early 10th century, finally ending in 938 after the defeat of the Southern Han armada by the Viet leader Ngô Quyền. This period saw three Chinese imperial dynasties rule over what is today northern Vietnam: Sui, Tang and Wu Zhou. The Sui dynasty ruled northern Vietnam from 602 to 618, and briefly reoccupied central Vietnam in 605. The successive Tang dynasty ruled northern Vietnam from 621 to 690, and again from 705 to 880. Between 690 and 705, the Tang dynasty was briefly interrupted by the Wu Zhou dynasty which maintained Chinese rule over Vietnam.

Around 540s, the region of Jiaozhou (northern Vietnam) saw the uprising of the local Lý clan led by Lý Bí.^[88] In 589, the Sui dynasty defeated the Chen dynasty and unified China proper. As the authority of the Sui gradually consolidated in this region, Lý Phật Tử, the ruler of Vạn Xuân in Jiaozhou recognized sui overlordship. In 595, king Sambhuvarman (r. 572–629) of Lâm Ấp, a Cham kingdom with its capital located around modern-day Da Nang or Trà Kiệu, prudently sent tribute to the Sui. However, there was a myth in China which postulated that Champa was an immensely rich area, sparking the interest of Sui officials.^[89]

In 601, the Chinese official Xi Linghu forwarded an imperial summons for Phật Tử to appear at Chang'an, the Sui capital. Deciding to resist this demand, Phật Tử sought to delay by requesting that the summons be postponed until after the new year. Xi approved the request, believing that he could keep Phật Tử's allegiance by exercising restraint. However, Xi was accused of taking a bribe from Phật Tử, and the court grew suspicious. When Phật Tử openly rebelled early in 602, Xi was promptly arrested; he died while being taken north.^[90] In 602, Emperor Wen of Sui ordered general Liu Fang to launch a surprise attack on Phật Tử from Yunnan with 27 battalions.^[91] Unprepared to resist an assault of this scale, Phật Tử heeded Fang's admonition to surrender and was sent to Chang'an. Lý Phật Tử and his subordinates were decapitated to preclude future trouble.^[91] From recaptured Jiaozhou, Yang Jian authorized Liu Fang to attack Lâm Ấp, located south of Jiaozhou.^[89]

The Sui invasion of Champa consisted of a land force and a naval squadron led by Liu Fang.^[89] Sambhuvarman deployed war elephants and confronted the Chinese. Linyi's elephant corps at first found some success against the invaders. Liu Fang then ordered troops to dig booby traps and covered them with camouflaged leaves and grass. The elephants alerted by traps, turning back and trampling on their own troops. Disarraying Cham army were then defeated by Chinese archers.^[92] The Chinese force broke through to the capital and pillaged the city. Among their spoils were eighteen golden tablets dedicated to the memory of the eighteen preceding kings of Lâm Ấp, a Buddhist library comprising 1,350 works in the local language, and an orchestra from a kingdom in the Mekong basin.^[93] The Sui immediately set up an administration in Lâm Ấp and divided the country into 3 counties: Tỷ Ảnh, Hải Âm and Tượng Lâm.^[94] The Sui effort to administer parts of Champa directly was short-lived. Sambuvarman reasserted his power and sent an embassy to the Sui to "acknowledge his fault."^[89] The Cham quickly regained independence during the troubles accompanying the collapse of the Sui empire, and sent a gift to the new Tang Empire's ruler in 623.^[94]

In 618, Emperor Gaozu of Tang overthrew the Sui dynasty and established the Tang dynasty. Qiu He first submitted to Xiao Xian's empire in 618, then to the Tang emperor in 622, incorporating northern Vietnam into the Tang dynasty.^[95] A local ruler of Jiuzhen (today's Thanh Hóa), Lê Ngọc, stayed loyal to Xiao Xian and fought against the Tang for another three years.

In 627, Emperor Taizong launched an administrative reform which reduced the number of provinces. In 679, Jiaozhou province was replaced with the Protectorate General to Pacify the South (Annan Duhufu). This administrative unit was used by the Tang to govern non-Chinese populations on the frontiers, similar to the Protectorate General to Pacify the West in Central Asia and the Protectorate General to Pacify the East in northern Korea.^[96] Every four years, the "southern selection" would choose aboriginal chiefs to be appointed to fill positions of the fifth degree and above. Taxation was more moderate than within the empire proper; the harvest tax was one-half the standard rate, an acknowledgement of the political problems inherent in ruling a non-Chinese population.^[97] Native girls of Vietnam: Tais, Viets and others were also targeted by the slave traders.^[98] The women of Viet tribes were most likely used as everyday household slaves and handmaidens during most of the Tang.^[99]

For the first time since the Han dynasty, Chinese schools were built, and dykes were constructed to protect the capital city of Songping (later Đại La). The Red River delta was the largest agricultural plain in the empire's south, with roads connecting Champa and Zhenla to the south and the southwest, and sea routes connected to the Indian Ocean.^[100] Buddhism flourished in Annan, although the Tang's official religion was Daoism. At least 6 monks from northern Vietnam traveled to China, Srivijaya, India and Sri Lanka during the Tang period.^[101] Very few natives engaged in the Confucian scholarship and civil service examination.^[102]

From the 7th to the 10th centuries, Champa entered its golden age. The Cham polities rose to become a naval power and Cham fleets controlled the trade in spices and silk between China, India, the Indonesian islands, and the Abbasid empire in Baghdad. They supplemented their income from the trade routes not only by exporting ivory and aloe, but also by engaging in piracy and raiding.^[77] However, the rising influence of Champa caught the attention of a neighbouring thalassocracy that considered Champa as a rival, the Javanese (Javaka, probably refers to Srivijaya, ruler of the Malay Peninsula, Sumatra and Java). In 767, the Tonkin coast was raided by a Javanese fleet (Daba) and Kunlun pirates,^[78] Champa was subsequently assaulted by Javanese or Kunlun vessels in 774 and 787.^[79] In 774 an assault was launched on Po-Nagar in Nha Trang where the pirates demolished temples, while in 787 an assault was launched on Virapura, near Phan Rang.^[80] The Javanese invaders continued to occupy southern Champa coastline until being driven off by Indravarman I (r. 787–801) in 799.^[81]

In 875, a new Buddhist dynasty founded by Indravarman II (r. ? – 893) moved the capital or the major center of Champa to the north again. Indravarman II established the city of Indrapura, near My Son and ancient Simhapura.^[82] Mahayana Buddhism eclipsed Hinduism, becoming the state religion.^[83] Art historians often attribute the period between 875 and 982 as the Golden Age of Champa art and Champa culture (distinguish with modern Cham culture).^[84] Unfortunately, a Vietnamese invasion in 982 led by king Le Hoan of Dai Viet, followed by Lưu Kế Tông (r. 986–989), a fanatical Vietnamese usurper who took the throne of Champa in 983,^[85] brought mass destruction to Northern Champa.^[86] Indrapura was still one of the major centers of Champa until being surpassed by Vijaya in the 12th century.^[87]

In 722, Mai Thúc Loan from Jiude (today Hà Tĩnh Province) led a large insurrection against Chinese rule. Styling himself "Swarthy Emperor" or "Black Emperor" (Hắc Đẽ), he rallied 400,000 people from 23 counties to join, and also allied with Champa and Chenla, an unknown kingdom named Jinlin ("Gold Neighbor") and other unnamed kingdoms.^[103] A Tang army of 100,000 under general Yang Zixu, including a multitude of mountain tribesmen who had remained loyal to the Tang, marched directly along the coast, following the old road built by Ma Yuan.^[103] Yang Zixu attacked Mai Thúc Loan by surprise and suppressed the rebellion in 723. The corpses of the Swarthy Emperor and his followers were piled up to form a huge mound and were left on public display to check further revolts.^[105] Later from 726 to 728, Yang Zixu suppressed other rebellions of Li and Nung peoples led by Chen Xingfan and Feng Lin in the north, who proclaimed the title "Emperor of Nanyue", causing another 80,000 deaths.^[104]

In 854, the new governor of Annan, Li Zhuo, provoked hostiles and conflicts with the mountain tribes by reducing the salt trade and killing powerful chieftains, resulting in the defection of prominent local leaders to the Nanzhao Kingdom. The local chief Lý Do Độc, the Đỗ clan, the warlord Chu Đạo Cổ, as well as others, submitted or allied with Nanzhao.^[106] In 858 they sacked the capital of Annan. In the same year the Tang court responded by appointing Wang Shi as the military governor of Annan, aiming to restore order, strengthen the defense of Songping.^[107] Wang Shi was recalled to deal with the rebellion of Qiu Fu in Zhejiang in late 860. Northern Vietnam then degenerated back to chaos and turmoil. The new Chinese military governor, Li Hu, executed Đỗ Thủ Trừng, a prominent local chief, thus alienating many of the powerful local clans of Annan.^[108] The Nanzhao army was initially welcomed by the locals, and their joint force captured Songping in January 861, forced Li Hu to flee.^[109] The Tang managed to retake the region in summer 861. In spring 863 Nanzhao and rebels numbered 50,000 under generals Yang Sijin and Duan Qiuqian launched the Siege of Songping. The city fell in late January as the Chinese army withdrew north.^[110] The Protectorate of Annan was abolished.^[111]

The Tang launched a counterattack in September 864 under Gao Pian, an experienced general who had fought the Türks and the Tanguts in the north. In winter 865–866, Gao Pian recaptured Songping and northern Vietnam, and expelled Nanzhao from the region.^[112] Gao punished local people who had allied with Nanzhao, executed Chu Đạo Cổ and 30,000 local rebels.^[113] In 868 he renamed the region to "The Peaceful Sea Army" (Jinghai guan). He rebuilt the citadel Sin Songping, named it Đại La, repaired 5,000 meters of damaged city wall and reconstructed 400,000 bays for its residents.^[112] He was well respected even by the later Vietnamese.^[114]

Since 905, Tĩnh Hải circuit had been ruled by local Vietnamese governors like an autonomous state.^[115] Tĩnh Hải circuit had to paid tributes for Later Liang dynasty to exchange political protection.^[116] In 923, the nearby Southern Han invaded Jinghai but was repelled by Vietnamese leader Dương Đình Nghệ.^[117] In 938, the Chinese state Southern Han once again sent a fleet to subdue the Vietnamese. General Ngô Quyền (r. 938–944), Dương Đình Nghệ's son-in-law, defeated the Southern Han fleet at the Battle of Bạch Đằng (938). He then proclaimed himself King Ngô, established a monarchy government in Cổ Loa and effectively began the age of independence for Vietnam.

Ngô Quyền in 938 declared himself king, but died after only 6 years. His untimely death after a short reign resulted in a power struggle for the throne, resulting in the country's first major civil war, the upheaval of the Twelve Warlords (Loạn Thập Nhị Sứ Quân). The war lasted from 944 to 968, until the clan led by Đinh Bộ Lĩnh defeated the other warlords, unifying the country.^[123] Đinh Bộ Lĩnh founded the Đinh dynasty and proclaimed himself Đinh Tiên Hoàng (Đinh the Majestic Emperor) and renamed the country from Tĩnh Hải quân to Đại Cồ Việt (literally "Great Viet"), with its capital in the city of Hoa Lư (modern-day Ninh Bình Province). The new emperor introduced strict penal codes to prevent chaos from happening again. He then tried to form alliances by granting the title of Queen to five women from the five most influential families. Đại La became the capital.

In 979, Emperor Đinh Tiên Hoàng and his crown prince Đinh Liễn were assassinated by Đỗ Thích, a government official, leaving his lone surviving son, the 6-year-old Đinh Toàn, to assume the throne. Taking advantage of the situation, the Song dynasty invaded Đại Cồ Việt. Facing such a grave threat to national independence, the commander of the armed forces, (Thập Đạo Tướng Quân) Lê Hoàn took the throne, replaced the house of Đinh and established the Early Lê dynasty. A capable military tactician, Lê Hoan realized the risks of engaging the mighty Song troops head on; thus, he tricked the invading army into Chi Lăng Pass, then ambushed and killed their commander, quickly ending the threat to his young nation in 981. The Song dynasty withdrew their troops and Lê Hoàn was referred to in his realm as Emperor Đại Hành (Đại Hành Hoàng Đế).^[124] Emperor Lê Đại Hành was also the first Vietnamese monarch who began the southward expansion process against the kingdom of Champa.

Emperor Lê Đại Hành's death in 1005 resulted in infighting for the throne amongst his sons. The eventual winner, Lê Long Đĩnh, became the most notorious tyrant in Vietnamese history. He devised sadistic punishments of prisoners for his own entertainment and indulged in deviant sexual activities. Toward the end of his short life – he died in 1009 at the age of 24 – Lê Long Đĩnh had become so ill, that he had to lie down when meeting with his officials in court.^[125]

In late 938, the Southern Han fleet led by Liu Hongcao met Ngô Quyền's fleet on the gate of the Bạch Đằng River. The Southern Han fleet consisted fast warships carrying fifty men on each–twenty sailors, twenty five warriors, and two crossbowmen.^[118] Ngô Quyền and his force had set up massive stakes tipped with iron foiled points on the river bed.^[119] When the river tide rose, the sharpened stakes were covered by water. As the Southern Han sailed into the estuary, Viets in smaller crafts went down and harassed the Southern Han warships, luring them to follow upstream. When the tide fell, Ngô Quyền's force counterattacked and pushed the enemy fleet back to the sea. The Southern Han ships were immobilized by the stakes.^[118] Half of the Han army died, either killed or drowned, including Liu Hongcao.^[119] When the news of the defeat reached Liu Yan on the sea, he retreated back to Guangzhou.^[120] In spring 939, Ngô Quyền proclaimed himself king and chose the town of Co Loa as the capital.^[121] The Battle of Bạch Đằng River put an end to the Third Era of Northern Domination (Chinese ruled Vietnam).^[122] It was considered the turning point in Vietnamese history.^[118]

Ngô Quyền in 938 declared himself king, but died after only 6 years. His untimely death after a short reign resulted in a power struggle for the throne, resulting in the country's first major civil war, the upheaval of the Twelve Warlords. The Anarchy of the 12 Warlords, also the Period of the 12 Warlords, was a period of chaos and civil war in the history of Vietnam, from 944 to 968 caused by the succession of the Ngô dynasty after the death of King Ngô Quyền.

Đinh Bộ Lĩnh, adopted son of Lord Trần Lãm who ruled the region of Bố Hải Khẩu (now Thái Bình Province), succeeded Lãm after his death. In 968, Đinh Bộ Lĩnh defeated the other eleven major warlords and reunified the nation under his rule. In the same year, Đinh Bộ Lĩnh ascended the throne, proclaiming himself emperor with the title Đinh Tiên Hoàng, establishing the Đinh dynasty, and he renamed the nation as Đại Cồ Việt ("Great Viet"). He moved the capital to Hoa Lư (modern-day Ninh Bình).

In 979, Emperor Đinh Tiên Hoàng and his crown prince Đinh Liễn were assassinated by Đỗ Thích, a government official, leaving his lone surviving son, the 6-year-old Đinh Toàn, to assume the throne. Taking advantage of the situation, the Song dynasty invaded Đại Cồ Việt. Facing such a grave threat to national independence, the commander of the armed forces, (Thập Đạo Tướng Quân) Lê Hoàn took the throne, replaced the house of Đinh and established the Early Lê dynasty. A capable military tactician, Lê Hoan realized the risks of engaging the mighty Song troops head on; thus, he tricked the invading army into Chi Lăng Pass, then ambushed and killed their commander, quickly ending the threat to his young nation in 981. The Song dynasty withdrew their troops and Lê Hoàn was referred to in his realm as Emperor Đại Hành (Đại Hành Hoàng Đế).^[126] Emperor Lê Đại Hành was also the first Vietnamese monarch who began the southward expansion process against the kingdom of Champa.

In October 979, Emperor Đinh Bộ Lĩnh and Prince Đinh Liễn of Dai Co Viet were killed by a eunuch named Đỗ Thích while they were sleeping in the courtyard of the palace. Their deaths resulted in a state of unrest throughout Dai Viet. After hearing the news, Ngô Nhật Khánh, who was still living out his exile in Champa, encouraged the Cham king Jaya Paramesvaravarman I to invade Đại Việt. The naval invasion was halted due to a typhoon.^[127] In the following years, the new Vietnamese ruler, Lê Hoàn, sent emissaries to Champa to announce his accession to the throne.^[128] However, Jaya Paramesvaravarman I detained them. As no peaceful reconciliation avail, Lê Hoàn used this action as a pretext for a retaliatory expedition to Champa.^[129] This marked the beginning of a southward Vietnamese advance against Champa. ^[130]

In 982, Lê Hoàn commanded the army and stormed the Cham capital of Indrapura (modern-day Quảng Nam). Jaya Paramesvaravarman I was killed while the invading force sacked Indrapura. In 983, after the war had devastated northern Champa, Lưu Kế Tông, a Vietnamese military officer, took advantage of the disruptions and seized power in Indrapura.^[131] In the same year, he successfully resisted Lê Hoàn's attempt to remove him from power.^[132] In 986, Indravarman IV died and Lưu Kế Tông proclaimed himself King of Champa.^[128] Following the usurpation of Lưu Kế Tông, many Chams and Muslims fled to Song China, particularly the Hainan and Guangzhou regions, to seek refuge.^[131] Following the death of Lưu Kế Tông in 989, the native Cham king Jaya Harivarman II was crowned.

When the king Lê Long Đĩnh died in 1009, a palace guard commander named Lý Công Uẩn was nominated by the court to take over the throne, and founded the Lý dynasty.^[133] This event is regarded as the beginning of another golden era in Vietnamese history, with the following dynasties inheriting the Lý dynasty's prosperity and doing much to maintain and expand it. The way Lý Công Uẩn ascended to the throne was rather uncommon in Vietnamese history. As a high-ranking military commander residing in the capital, he had all opportunities to seize power during the tumultuous years after Emperor Lê Hoàn's death, yet preferring not to do so out of his sense of duty. He was in a way being "elected" by the court after some debate before a consensus was reached.^[134] During Lý Thánh Tông's reign, the official name of the state was changed from Đại Cồ Việt to Đại Việt, a name that would remain Vietnam's official name until the onset of the 19th century.

Domestically, while the Lý emperors were devout in their adherence to Buddhism, the influence of Confucianism from China was on the rise, with the opening of the Temple of Literature in 1070, built for the veneration of the Confucius and his disciples. Six years later in 1076, the Quốc Tử Giám (Guozijian) was established within the same complex; Initially the education was limited to the children of the emperor, the imperial family as well as mandarin and nobility, serving as Vietnam's first university institution. The first imperial examination was held in 1075 and Lê Văn Thịnh became the first Trạng Nguyên of Vietnam.

Politically, the dynasty established an administration system based on the rule of law rather than on autocratic principles. They chose the Đại La Citadel as the capital (later renamed Thăng Long and subsequently Hanoi). Ly Dynasty held onto power in part due to their economic strength, stability and general popularity among the population rather than by military means like previous dynasties. This set off a historical precedent for following dynasties, as prior to the Ly Dynasty, most Vietnamese dynasties lasted very briefly, often fall to the state of decline following the respective dynasty founder's death. Noblemen scholars such as Lê Văn Thịnh, Bùi Quốc Khái, Doãn Tử Tư, Đoàn Văn Khâm, Lý Đạo Thành, and Tô Hiến Thành made vast contributions culturally and politically, allowing the dynasty to flourish for 216 years.

In 1074, Harivarman IV became king of Champa. He had close ties to Song China and made peace with Dai Viet, but provoked a war with the Khmer Empire.^[135] In 1080, a Khmer army attacked Vijaya and other centers in northern Champa. Temples and monasteries were sacked and cultural treasures were carried off. After much chaos, Cham troops under King Harivarman were able to defeat the invaders and restore the capital and temples.^[136] Subsequently, his raiding forces penetrated Cambodia as far as Sambor and the Mekong, where they destroyed all religious sanctuaries.^[137]

The Vietnamese during Lý dynasty had one major war with Song China, and a few invasive campaigns against neighboring Champa in the south.^[138] The most notable conflict took place on Chinese territory Guangxi in late 1075. Upon learning that a Song invasion was imminent, the Vietnamese army under the command of Lý Thường Kiệt, and Tông Đản used amphibious operations to preemptively destroy three Song military installations at Yongzhou, Qinzhou, and Lianzhou in present-day Guangdong and Guangxi. The Song dynasty took revenge and invaded Đại Việt in 1076, but the Song troops were held back at the Battle of Như Nguyệt River commonly known as the Cầu river, now in Bắc Ninh province about 40 km from the current capital, Hanoi. Neither side was able to force a victory, so the Vietnamese court proposed a truce, which the Song emperor accepted.^[139]

Champa and the powerful Khmer Empire took advantage of Đại Việt's distraction with the Song to pillage Đại Việt's southern provinces. Together they invaded Đại Việt in 1128 and 1132. In 1127, the 12-years-old Crown Prince Lý Dương Hoán became the new ruler of Đại Việt.^{[140 ]}Suryavarman II demanded Đại Việt to pay tribute for the Khmer Empire, but the Vietnamese refused to pay tribute to the Khmers. Suryavarman II decided to expand his territory northward into Vietnamese territory.^[141]

The first attack was in 1128 when King Suryavarman II led 20,000 soldiers from Savannakhet to Nghệ An but were routed in battle. The following year Suryavarman continued skirmishes on land and sent 700 ships to bombard the coastal areas of Đại Việt. The warfare escalated in 1132 when Khmer Empire and Champa jointly invaded Đại Việt, briefly seizing Nghệ An. In 1136, Duke Đỗ Anh Vũ led an expedition with thirty thousand troops into Khmer territories, but his army later retreated after subdued highland tribes in Xiangkhoang.^[141] By 1136, King Jaya Indravarman III of Champa made peace with the Vietnamese, which led to the Khmer–Cham War. In 1138, Lý Thần Tông died aged 22 from a disease and was succeeded by his two years old son Lý Anh Tông. Suryavarman II led several more attacks on Đại Việt until his death in 1150.^[142]

After a failed attempt to seize seaports in southern Đại Việt, Suryavarman turned to invade Champa in 1145 and sacked Vijaya, ending the reign of Jaya Indravarman III and destroying the temples at Mỹ Sơn.^[143] Inscriptional evidence suggests that Suryavarman II died between 1145 CE and 1150 CE, possibly during a military campaign against Champa. He was succeeded by Dharanindravarman II, a cousin, son of the brother of the king's mother. A period of weak rule and feuding began.

After securing peace with Đại Việt in 1170, Cham forces under Jaya Indravarman IV invaded the Khmer Empire over land with inconclusive results.^[144] That year, a Chinese official from Hainan had witnessed elephant duel battles between Cham and Khmer armies, henceforth convincing the Cham king to offer war horse purchases from China, but the offer was rejected by the Song court multiple times. In 1177, however, his troops launched a surprise attack against the Khmer capital of Yasodharapura from warships ploted up the Mekong River to the great lake Tonlé Sap and killed the Khmer king Tribhuvanadityavarman.^[145] Multiple-bow siege crossbows were introduced to Champa from Song dynasty in 1171, and later were mounted on the backs of Cham and Vietnamese war elephants. They were deployed by the Cham during the siege of Angkor, which was lightly defended by wooden palisades, leading to the Cham occupation of Cambodia for the next four years.^[146] The Khmer empire was in the verge of collapse. Jayavarman VII from the north coalesced an army to battle the invaders. He had campaigned against the Chams in his youth, in the 1140s, and participated in a campaign in Cham capital Vijaya. His army won a series of unprecedented victories over the Cham, and by 1181 after winning a decisive naval battle, Jayavarman had rescued the empire and expelled the Cham.^[147]

In 1190, the Khmer king Jayavarman VII appointed a Cham prince named Vidyanandana, who had defected to Jayavarman in 1182 and had been educated at Angkor, to lead the Khmer army. Vidyanandana defeated the Chams, and proceeded to occupy Vijaya and captured Jaya Indravarman IV, whom he sent back to Angkor as a prisoner.^[147] Adopting the title of Shri Suryavarmadeva (or Suryavarman), Vidyanandana made himself king of Panduranga, which became a Khmer vassal. He made Prince In, a brother-in-law of Jayavarman VII, "King Suryajayavarmadeva in the Nagara of Vijaya". In 1191, a revolt at Vijaya drove Suryajayavarman back to Cambodia and enthroned Jaya Indravarman V. Vidyanandana, assisted by Jayavarman VII, retook Vijaya, killing both Jaya Indravarman IV and Jaya Indravarman V, then "reigned without opposition over the Kingdom of Champa,"^[148] declaring his independence from the Khmer Empire. Jayavarman VII responded by launching several invasions of Champa in 1192, 1195, 1198–1199, 1201-1203. The Khmer later also had double bow crossbows mounted on elephants, which Michel Jacq Hergoualc’h suggest were elements of Cham mercenaries in Jayavarman VII's army.^[149]

Khmer armies under Jayavarman VII continued campaigning against Champa until the Chams were finally defeated in 1203.^[150] A Cham renegade-Prince ong Dhanapatigräma, overthrew and expelled his ruling nephew Vidyanandana/Suryavarman to Dai Viet, completing the Khmer conquest of Champa.^[151] From 1203 to 1220, Champa as a Khmer province was ruled by a puppet government led by either ong Dhanapatigräma and then prince Angsaräja, son of Harivarman I, who would later become Jaya Paramesvaravarman II. In 1207, Angsaräja accompanied a Khmer army with Burmese and Siamese mercenacy contingents to battle against the Yvan (Dai Viet) army.^[152] Following the dwindling Khmer military presence and voluntary Khmer evacuation of Champa in 1220, Angsaräja took over the reins of government peacefully, proclaiming himself Jaya Paramesvaravarman II, and restored Champa's independence.^[153]

Toward the declining Lý monarch's power in the late 12th century, the Trần clan from Nam Định eventually rise to power.^[154] In 1224, powerful court minister Trần Thủ Độ forced the emperor Lý Huệ Tông to become a Buddhist monk and Lý Chiêu Hoàng, Huệ Tông's 8-year-old young daughter, to become ruler of the country.^[155] Trần Thủ Độ then arranged the marriage of Chiêu Hoàng to his nephew Trần Cảnh and eventually had the throne transferred to Trần Cảnh, thus begun the Trần dynasty.^[156] The Trần dynasty, officially Great Việt, was a Vietnamese dynasty that ruled from 1225 to 1400. The Trần dynasty defeated three Mongol invasions, most notably during the decisive Battle of Bạch Đằng River in 1288. The final emperor of the dynasty was Thiếu Đế, who was forced to abdicate the throne in 1400, at the age of five years old in favor of his maternal grandfather, Hồ Quý Ly.

The Trần improved Chinese gunpowder,^[157] enabling them to expand southward to defeat and vassalize the Champa.^[158] They also started using paper money for the first time in Vietnam.^[159] The period was considered a golden age in Vietnamese language, arts, and culture.^[160] The first pieces of Chữ Nôm literature were written during this period,^[161] while the introduction of vernacular Vietnamese into the court was established, alongside Chinese.^[162] This laid the foundation for the further development and solidifying of the Vietnamese language and identity.

Four major military campaigns were launched by the Mongol Empire, and later the Yuan dynasty, against the kingdom of Đại Việt (modern-day northern Vietnam) ruled by the Trần dynasty and the kingdom of Champa (modern-day central Vietnam) in 1258, 1282–1284, 1285, and 1287–88. The first invasion began in 1258 under the united Mongol Empire, as it looked for alternative paths to invade the Song dynasty. The Mongol general Uriyangkhadai was successful in capturing the Vietnamese capital Thang Long (modern-day Hanoi) before turning north in 1259 to invade the Song dynasty in modern-day Guangxi as part of a coordinated Mongol attack with armies attacking in Sichuan under Möngke Khan and other Mongol armies attacking in modern-day Shandong and Henan.^[163] The first invasion also established tributary relations between the Vietnamese kingdom, formerly a Song dynasty tributary state, and the Yuan dynasty. In 1282, Kublai Khan and the Yuan dynasty launched a naval invasion of Champa that also resulted in the establishment of tributary relations.

Intending to demand greater tribute and direct Yuan oversight of local affairs in Đại Việt and Champa, the Yuan launched another invasion in 1285. The second invasion of Đại Việt failed to accomplish its goals, and the Yuan launched a third invasion in 1287 with the intent of replacing the uncooperative Đại Việt ruler Trần Nhân Tông with the defected Trần prince Trần Ích Tắc. The key to Annam's successes was to avoid the Mongols' strength in open field battles and city sieges—the Trần court abandoned the capital and the cities. The Mongols were then countered decisively at their weak points, which were battles in swampy areas such as Chương Dương, Hàm Tử, Vạn Kiếp and on rivers such as Vân Đồn and Bạch Đằng. The Mongols also suffered from tropical diseases and loss of supplies to Trần army's raids. The Yuan-Trần war reached its climax when the retreating Yuan fleet was decimated at the Battle of Bạch Đằng (1288). The military architect behind Annam's victories was Commander Trần Quốc Tuấn, more popularly known as Trần Hưng Đạo. By the end of the second and third invasions, which involved both initial successes and eventual major defeats for the Mongols, both Đại Việt and Champa decided to accept the nominal supremacy of the Yuan dynasty and became tributary states to avoid further conflict.^[164]

The fourteenth century saw a great void of indigenous information within Champa, with no inscription was erected after 1307, until 1401, although the Cham annals still has a list of 14th century kings of Panduranga. Religious construction and art came to a standstill, and sometimes degraded.^[171] These could be hints of decline of Indic culture in Champa, or consequence of Champa's devastating war with the Dai Viet and the Sukhothai.

For the reasons of the complete blackout of 14th-century Cham historiography, Pierre Lafont argues, were perhaps due to Champa's previous long conflicts with their neighbors, the Angkor Empire and Dai Viet, and recently Mongols, had caused mass destruction and socio-cultural breakdown. Unraveled grievances and deteriorating economic conditions continued to pile up. Engraving Sanskrit inscriptions in Champa, the language mainly used for religious purposes, ceased to exist by 1253.^[172] Some cities and farmland were left abandoned, such as Tra Kieu (Simhapura).^[173] The gradual religious shift to Islam in Champa from 11th to 15th centuries undermined the established Hindu-Buddhist kingship and the king's spiritual divinity, resulting in growing royal frustrations and strife between the Cham aristocracy. These led to constant instability and the ultimate decline of Champa during the 14th century.^[174]

Because none inscription within Champa during this period have been found, it's insecure to establish a lineage of Champa rulers without knowing what their native names and which years they reigned. Historians have to recite various Vietnamese chronicles and Chinese annals to reconstruct Champa during the 14th century cautiously.^[175]

The Kingdom of Sukhothai attacked Kingdom of Champa, a vassal state of kingdom of Đại Việt from the mountains but was repulsed.^[170]

The Vietnamese waged war against the southern kingdom of Champa, continuing the Vietnamese long history of southern expansion (known as Nam tiến) that had begun shortly after gaining independence in the 10th century. Often, they encountered strong resistance from the Chams. After the successful alliance with Champa during the Mongol invasion, king Trần Nhân Tông of Đại Việt gained two Champa provinces, located around present-day Huế, through the peaceful means of the political marriage of Princess Huyền Trân to Cham king Jaya Simhavarman III. Not long after the nuptials, the king died, and the princess returned to her northern home in order to avoid a Cham custom that would have required her to join her husband in death.^[165] In 1307, the new Cham king Simhavarman IV (r. 1307–1312), set out to retake the two provinces to protest against the Vietnamese agreement but was defeated and taken as a prisoner. Champa became a Vietnamese vassal state in 1312.^[166] The Cham revolted in 1318. In 1326 they managed to defeat the Vietnamese and reasserted independence.^[167] Royal upheaval within the Cham court resumed until 1360, when a strong Cham king was enthroned, known as Po Binasuor (r. 1360–90). During his thirty-year reign, Champa gained its momentum peak. Po Binasuor annihilated the Vietnamese invaders in 1377, ransacked Hanoi in 1371, 1378, 1379, and 1383, nearly had united all Vietnam for the first time by the 1380s.^[168] During a naval battle in early 1390, the Cham conqueror however was killed by Vietnamese firearm units, thus ending the short-lived rising period of the Cham kingdom. During the next decades, Champa returned to its status quo of peace. After much warfare and dismal conflicts, king Indravarman VI (r. 1400–41) reestablished relations with the second kingdom of Dai Viet's ruler Le Loi in 1428.^[169]

The wars with Champa and the Mongols left Đại Việt exhausted and bankrupt. The Trần family was in turn overthrown by one of its own court officials, Hồ Quý Ly. Hồ Quý Ly forced the last Trần emperor to abdicate and assumed the throne in 1400. He changed the country name to Đại Ngu and moved the capital to Tây Đô, Western Capital, now Thanh Hóa. Thăng Long was renamed Đông Đô, Eastern Capital. Although widely blamed for causing national disunity and losing the country later to the Ming Empire, Hồ Quý Ly's reign actually introduced a lot of progressive, ambitious reforms, including the addition of mathematics to the national examinations, the open critique of Confucian philosophy, the use of paper currency in place of coins, investment in building large warships and cannons, and land reform. He ceded the throne to his son, Hồ Hán Thương, in 1401 and assumed the title Thái Thượng Hoàng, in similar manner to the Trần kings.^[176] The Hồ dynasty was conquered by the Chinese Ming dynasty in 1407.

The Fourth Era of Northern Domination was a period of Vietnamese history, from 1407 to 1427, during which Vietnam was ruled by the Chinese Ming dynasty as the province of Jiaozhi (Giao Chỉ). Ming rule was established in Vietnam following its conquest of the Hồ dynasty. The previous periods of Chinese rule, collectively known as Bắc thuộc, lasted much longer and amounted to around 1000 years. The fourth period of Chinese rule over Vietnam was eventually ended with the establishment of the Later Lê dynasty.

The Lê dynasty, also known in historiography as the Later Lê dynasty, was the longest-ruling Vietnamese dynasty, having ruled from 1428 to 1789, with an interregnum between 1527 and 1533. The Lê dynasty is divided into two historical periods: the Primitive Lê dynasty (1428–1527) before the usurpation by the Mạc dynasty, in which emperors ruled in their own right, and the Revival Lê dynasty (1533–1789), in which puppet emperors reigned under the auspices of the powerful Trịnh family. The Revival Lê dynasty was marked by two lengthy civil wars: the Lê–Mạc War (1533–1592) in which two dynasties battled for legitimacy in northern Vietnam and the Trịnh–Nguyễn War (1627–1672, 1774-1777) between the Trịnh lords in North and the Nguyễn lords of the South.

The dynasty officially began in 1428 with the enthronement of Lê Lợi after he drove the Ming army from Vietnam. The dynasty reached its peak during the reign of Lê Thánh Tông and declined after his death in 1497. In 1527, the Mạc dynasty usurped the throne; when the Lê dynasty was restored in 1533, the Mạc fled to the far north and continued to claim the throne during the period known as Southern and Northern Dynasties. The restored Lê emperors held no real power, and by the time the Mạc dynasty was finally eradicated in 1677, actual power lay in the hands of the Trịnh lords in the North and Nguyễn lords in the South, both ruling in the name of the Lê emperor while fighting each other. The Lê dynasty officially ended in 1789, when the peasant uprising of the Tây Sơn brothers defeated both the Trịnh and the Nguyễn, ironically in order to restore power to the Lê dynasty.

Overpopulation and land shortages stimulated a Vietnamese expansion south. The Lê dynasty continued the Nam tiến expansion of Vietnam's borders southwards through the domination of the Kingdom of Champa and expedition into today Laos and Myanmar, nearly reaching Vietnam's modern borders by the time of the Tây Sơn uprising. It also saw massive changes to Vietnamese society: the previously Buddhist state became Confucian after the preceding 20 years of Ming rule. The Lê emperors instituted many changes modeled after the Chinese system, including the civil service and laws. Their long-lasting rule was attributed to the popularity of the early emperors. Lê Lợi's liberation of the country from 20 years of Ming rule and Lê Thánh Tông's bringing the country into a golden age was well-remembered by the people. Even though the restored Lê emperors' rule was marked by civil strife and constant peasant uprisings, few dared to openly challenge their power for fear of losing popular support. The Lê dynasty also was the period Vietnam saw the coming of Western Europeans and Christianity in early 16th-century.

Overpopulation and land shortages stimulated a Vietnamese expansion south. In 1471, Dai Viet troops led by king Lê Thánh Tông invaded Champa and captured its capital Vijaya. This event effectively ended Champa as a powerful kingdom, although some smaller surviving Cham states lasted for a few centuries more. It initiated the dispersal of the Cham people across Southeast Asia. With the kingdom of Champa mostly destroyed and the Cham people exiled or suppressed, Vietnamese colonization of what is now central Vietnam proceeded without substantial resistance. However, despite becoming greatly outnumbered by Vietnamese settlers and the integration of formerly Cham territory into the Vietnamese nation, the majority of Cham people nevertheless remained in Vietnam and they are now considered one of the key minorities in modern Vietnam. Vietnamese armies also raided the Mekong Delta, which the decaying Khmer Empire could no longer defend.

The Đại Việt–Lan Xang War of 1479–84, also known as the White Elephant War,^[177] was a military conflict precipitated by the invasion of the Lao kingdom of Lan Xang by the Vietnamese Đại Việt Empire. The Vietnamese invasion was a continuation of Emperor Lê Thánh Tông's expansion, by which Đại Việt had conquered the kingdom of Champa in 1471. The conflict grew into a wider conflagration involving the Ai-Lao people from Sip Song Chau Tai along with the Mekong river valley Tai peoples from the Yuan kingdom of Lan Na, Lü kingdom Sip Song Pan Na (Sipsong Panna), to Muang along the upper Irawaddy river.^[178] The conflict ultimately lasted approximately five years growing to threatened the southern border of Yunnan and raising the concerns of Ming China.^[179] Early gunpowder weapons played a major role in the conflict, enabling Đại Việt's aggression. Early success in the war allowed Đại Việt to capture the Lao capital of Luang Prabang and destroy the Muang Phuan city of Xiang Khouang. The war ended as a strategic victory for Lan Xang, as they were able to force the Vietnamese to withdraw with the assistance of Lan Na and Ming China.^[180] Ultimately the war contributed to closer political and economic ties between Lan Na, Lan Xang, and Ming China. In particular, Lan Na's political and economic expansion led to a "golden age" for that kingdom.

The Northern and Southern dynasties in the history of Vietnam, spanning from 1533 to 1592, was a political period in the 16th century during which the Mạc dynasty (Northern dynasty), established by Mạc Đăng Dung in Đông Đô, and the Revival Lê dynasty (Southern dynasty) based in Tây Đô were in contention. For most of the period, these two dynasties fought a lengthy war known as the Lê–Mạc War. Initially, the domain of the Southern court was confined within Thanh Hoa province. After the expedition of Nguyễn Hoàng to reclaim Lê territory in the South from Mạc garrison force, Northern dynasty only controlled the provinces from Thanh Hoa up North. Both dynasties claimed to be the sole legitimate dynasty of Vietnam. The nobles and their clansmen switched side frequently to the extent that loyal retainers such as Prince Mạc Kính Điển were praised even by their foes as rare virtuous men. As lords without land, these nobles and their armies behaved a little or no better than petty thieves, raiding and looting the farmers to feed themselves. This state of chaos brought along the destruction of the countryside and reduced many formerly prosperous cities such as Đông Kinh to poverty. The two dynasties fought for nearly sixty years, ended in 1592 when the Southern dynasty defeated the North and recaptured Đông Kinh. However, Mac family members had maintained an autonomous rule in Cao Bằng under the protectorate of Chinese dynasties until 1677.

The civil war between the Lê-Trịnh and Mạc dynasties ended in 1592, when the army of Trịnh Tùng conquered Hanoi and executed king Mạc Mậu Hợp. Survivors of the Mạc royal family fled to the northern mountains in the province of Cao Bằng and continued to rule there until 1677 when Trịnh Tạc conquered this last Mạc territory. The Lê monarchs, ever since Nguyễn Kim's restoration, only acted as figureheads. After the fall of the Mạc dynasty, all real power in the north belonged to the Trịnh lords. Meanwhile, the Ming court reluctantly decided on a military intervention into the Vietnamese civil war, but Mạc Đăng Dung offered ritual submission to the Ming Empire, which was accepted.

In the year 1600, Nguyễn Hoàng also declared himself Lord (officially "Vương") and refused to send more money or soldiers to help the Trịnh. He also moved his capital to Phú Xuân, modern-day Huế. Trịnh Tráng succeeded Trịnh Tùng, his father, upon his death in 1623. Tráng ordered Nguyễn Phúc Nguyên to submit to his authority. The order was refused twice. In 1627, Trịnh Tráng sent 150,000 troops southward in an unsuccessful military campaign. The Trịnh were much stronger, with a larger population, economy and army, but they were unable to vanquish the Nguyễn, who had built two defensive stone walls and invested in Portuguese artillery.

The Trịnh–Nguyễn War lasted from 1627 until 1672. The Trịnh army staged at least seven offensives, all of which failed to capture Phú Xuân. For a time, starting in 1651, the Nguyễn themselves went on the offensive and attacked parts of Trịnh territory. However, the Trịnh, under a new leader, Trịnh Tạc, forced the Nguyễn back by 1655. After one last offensive in 1672, Trịnh Tạc agreed to a truce with the Nguyễn Lord Nguyễn Phúc Tần. The country was effectively divided in two.

The Trịnh–Nguyễn War gave European traders the opportunities to support each side with weapons and technology: the Portuguese assisted the Nguyễn in the South while the Dutch helped the Trịnh in the North. The Trịnh and the Nguyễn maintained a relative peace for the next hundred years, during which both sides made significant accomplishments. The Trịnh created centralized government offices in charge of state budget and producing currency, unified the weight units into a decimal system, established printing shops to reduce the need to import printed materials from China, opened a military academy, and compiled history books.

Meanwhile, the Nguyễn lords continued the southward expansion by the conquest of the remaining Cham land. Việt settlers also arrived in the sparsely populated area known as "Water Chenla", which was the lower Mekong Delta portion of the former Khmer Empire. Between the mid-17th century to mid-18th century, as the former Khmer Empire was weakened by internal strife and Siamese invasions, the Nguyễn Lords used various means, political marriage, diplomatic pressure, political and military favors, to gain the area around present-day Saigon and the Mekong Delta. The Nguyễn army at times also clashed with the Siamese army to establish influence over the former Khmer Empire.

Việt settlers arrived in the sparsely populated area known as "Water Chenla", which was the lower Mekong Delta portion of the former Khmer Empire. Between the mid-17th century to mid-18th century, as the former Khmer Empire was weakened by internal strife and Siamese invasions, the Nguyễn Lords used various means, political marriage, diplomatic pressure, political and military favors, to gain the area around present-day Saigon and the Mekong Delta. The Nguyễn army at times also clashed with the Siamese army to establish influence over the former Khmer Empire.

The Tây Sơn wars or Tây Sơn rebellion were a series of military conflicts association followed the Vietnamese peasant uprising of Tây Sơn led three brothers Nguyễn Nhạc, Nguyễn Huệ, and Nguyễn Lữ. They began in 1771 and ended in 1802 when Nguyễn Phúc Ánh or Emperor Gia Long, a descendant of the Nguyễn lord, defeated the Tây Sơn and reunited Đại Việt, then renamed the country to Vietnam.

In 1771, the Tây Sơn revolution broke out in Quy Nhon, which was under the control of the Nguyễn lord.^[181] The leaders of this revolution were three brothers named Nguyễn Nhạc, Nguyễn Lữ, and Nguyễn Huệ, not related to the Nguyễn lord's family. In 1773, Tây Sơn rebels took Quy Nhon as the capital of the revolution. Tây Sơn brothers' forces attracted many poor peasants, workers, Christians, ethnic minorities in the Central Highlands and Cham people who had been oppressed by the Nguyễn Lord for a long time,^[182] and also attracted to ethnic Chinese merchant class, who hope the Tây Sơn revolt will spare down the heavy tax policy of the Nguyễn Lord, however their contributions later were limited due to Tây Sơn's nationalist anti-Chinese sentiment.^[181] By 1776, the Tây Sơn had occupied all of the Nguyễn Lord's land and killed almost the entire royal family. The surviving prince Nguyễn Phúc Ánh (often called Nguyễn Ánh) fled to Siam, and obtained military support from the Siamese king. Nguyễn Ánh came back with 50,000 Siamese troops to regain power, but was defeated at the Battle of Rạch Gầm–Xoài Mút and almost killed. Nguyễn Ánh fled Vietnam, but he did not give up.^[183]

The Tây Sơn army commanded by Nguyễn Huệ marched north in 1786 to fight the Trịnh Lord, Trịnh Khải. The Trịnh army failed and Trịnh Khải committed suicide. The Tây Sơn army captured the capital in less than two months. The last Lê emperor, Lê Chiêu Thống, fled to Qing China and petitioned the Qianlong Emperor in 1788 for help. The Qianlong Emperor supplied Lê Chiêu Thống with a massive army of around 200,000 troops to regain his throne from the usurper. In December 1788, Nguyễn Huệ–the third Tây Sơn brother–proclaimed himself Emperor Quang Trung and defeated the Qing troops with 100,000 men in a surprise 7 day campaign during the lunar new year (Tết). There was even a rumor saying that Quang Trung had also planned to conquer China, although it was unclear. During his reign, Quang Trung envisioned many reforms but died by unknown reason on the way march south in 1792, at the age of 40. During the reign of Emperor Quang Trung, Đại Việt was in fact divided into three political entities.^[184] The Tây Sơn leader, Nguyễn Nhạc, ruled the centre of the country from his capital Qui Nhơn. Emperor Quang Trung ruled the north from the capital Phú Xuân Huế. In the South. He officially funded and trained the Pirates of the South China Coast – one of the most strongest and feared pirate army in the world late 18th century–early 19th century.^[185] Nguyễn Ánh, assisted by many talented recruits from the South, captured Gia Định (present-day Saigon) in 1788 and established a strong base for his force.^[186]

After Quang Trung's death in September 1792, the Tây Sơn court became unstable as the remaining brothers fought against each other and against the people who were loyal to Nguyễn Huệ's young son. Quang Trung's 10-years-old son Nguyễn Quang Toản succeeded the throne, became Cảnh Thịnh Emperor, the third ruler of the Tây Sơn dynasty. In the South, lord Nguyễn Ánh and the Nguyễn royalists were assisted with French, Chinese, Siamese and Christian supports, sailed north in 1799, capturing Tây Sơn's stronghold Quy Nhon.^[187] In 1801, his force took Phú Xuân, the Tây Sơn capital. Nguyễn Ánh finally won the war in 1802, when he sieged Thăng Long (Hanoi) and executed Nguyễn Quang Toản, along with many Tây Sơn royals, generals and officials. Nguyễn Ánh ascended the throne and called himself Emperor Gia Long. Gia is for Gia Định, the old name of Saigon; Long is for Thăng Long, the old name of Hanoi. Hence Gia Long implied the unification of the country. As China for centuries had referred to Đại Việt as Annam, Gia Long asked the Manchu Qing emperor to rename the country, from Annam to Nam Việt. To prevent any confusion of Gia Long's kingdom with Triệu Đà's ancient kingdom, the Manchu emperor reversed the order of the two words to Việt Nam.

In 1769, King Taksin of Siam invaded and occupied portions of Cambodia. The following year a proxy war between Vietnam and Siam erupted in Cambodia when the Nguyễn Lords responded by attacking Siamese cities. At the outset of the war, Taksin advanced through Cambodia and placed Ang Non II on the Cambodian throne. The Vietnamese responded by recapturing the Cambodian capital and installing Outey II as their preferred monarch. In 1773, the Vietnamese made peace with the Siamese in order to deal with the Tây Sơn rebellion, which was a result of the war with Siam. Two years later Ang Non II was proclaimed the ruler of Cambodia.

The Nguyễn dynasty was the last Vietnamese dynasty, which was preceded by the Nguyễn lords and ruled the unified Vietnamese state independently from 1802 to 1883 before being under French protectorate. During its existence, the empire expanded into modern-day southern Vietnam, Cambodia, and Laos through a continuation of the centuries-long Nam tiến and Siamese–Vietnamese wars. With the French conquest of Vietnam, Nguyễn dynasty was forced to give up the sovereignty over parts of Southern Vietnam by France in 1862 and 1874, and after 1883 the Nguyễn dynasty only nominally ruled the French protectorates of Annam (in Central Vietnam) as well as Tonkin (in Northern Vietnam). They later canceled treaties with France and were the Empire of Vietnam for a short time until 25 August 1945.

The Nguyễn Phúc family established feudal rule over large amounts of territory as the Nguyễn lords (1558-1777, 1780-1802) by the 16th century before defeating the Tây Sơn dynasty and establishing their own imperial rule in the 19th century. The dynastic rule began with Gia Long ascending the throne in 1802, after ending the previous Tây Sơn dynasty. The Nguyễn dynasty was gradually absorbed by France over the course of several decades in the latter half of the 19th century, beginning with the Cochinchina Campaign in 1858 which led to the occupation of the southern area of Vietnam. A series of unequal treaties followed; the occupied territory became the French colony of Cochinchina in the 1862 Treaty of Saigon, and the 1863 Treaty of Huế gave France access to Vietnamese ports and increased control of its foreign affairs. Finally, the 1883 and 1884 Treaties of Huế divided the remaining Vietnamese territory into the protectorates of Annam and Tonkin under nominal Nguyễn Phúc rule. In 1887, Cochinchina, Annam, Tonkin, and the French Protectorate of Cambodia were grouped together to form French Indochina.

The Nguyễn dynasty remained the formal emperors of Annam and Tonkin within Indochina until World War II. Japan had occupied Indochina with French collaboration in 1940, but as the war seemed increasingly lost, overthrew the French administration in March 1945 and proclaimed independence for its constituent countries. The Empire of Vietnam under the Bảo Đại Emperor was a nominally independent Japanese puppet state during the last months of the war. It ended with the Bảo Đại Emperor's abdication following the surrender of Japan and August Revolution by the anti-colonial Việt Minh in the August 1945. This ended the 143-year rule of the Nguyễn dynasty.^[188]

The Siamese–Vietnamese War of 1831–1834 was sparked by a Siamese invasion force under General Bodindecha that was attempting to conquer Cambodia and southern Vietnam. After initial success and the defeat of the Khmer Army at the Battle of Kompong Cham in 1832, the Siamese advance was repelled in southern Vietnam in 1833 by the military forces of the Nguyễn dynasty. Upon the outbreak of a general uprising in Cambodia and Laos, the Siamese withdrew, and Vietnam was left in control of Cambodia.

The Lê Văn Khôi revolt was an important revolt in 19th-century Vietnam, in which southern Vietnamese, Vietnamese Catholics, French Catholic missionaries and Chinese settlers under the leadership of Lê Văn Khôi opposed the Imperial rule of Emperor Minh Mạng. As Minh Mạng raised an army to quell the rebellion, Lê Văn Khôi fortified himself into the Saigon fortress and asked for the help of the Siamese. Rama III, king of Siam, accepted the offer and sent troops to attack the Vietnamese provinces of Ha-tien and An-giang and Vietnamese imperial forces in Laos and Cambodia. These Siamese and Vietnamese forces were repelled in summer 1834 by General Truong Minh Giang. It took three years for Minh Mạng to quell the rebellion and the Siamese offensive.The failure of the revolt had a disastrous effect on the Christian communities of Vietnam. New waves of persecutions against Christians followed, and demands were made to find and execute remaining missionaries.

The Siamese–Vietnamese War of 1841–1845 was a military conflict between the Đại Nam, ruled by Emperor Thiệu Trị, and the Kingdom of Siam, under the rule of Chakri King Nangklao. The rivalry between Vietnam and Siam over the control of the Cambodian heartlands in the Lower Mekong basin had intensified after Siam had attempted to conquer Cambodia during the previous Siamese–Vietnamese War (1831–1834). Vietnamese Emperor Minh Mạng installed Princess Ang Mey to rule Cambodia as a puppet queen regnant of his choice in 1834 and declared full suzerainty over Cambodia, which he demoted to Vietnam's 32nd province, the Western Commandery (Tây Thành Province).^[189] In 1841, Siam seized the opportunity of discontent to aid the Khmer revolt against Vietnamese rule. King Rama III sent an army to enforce Prince Ang Duong's installation as King of Cambodia. After four years of attrition warfare, both parties agreed to compromise and placed Cambodia under joint rule.^[190]

The French colonial empire was heavily involved in Vietnam in the 19th century; often French intervention was undertaken in order to protect the work of the Paris Foreign Missions Society in the country. To expand French influence in Asia, Napoleon III of France ordered Charles Rigault de Genouilly with 14 French gunships to attack the port of Đà Nẵng (Tourane) in 1858. The attack caused significant damage, yet failed to gain any foothold, in the process being afflicted by the humidity and tropical diseases. De Genouilly decided to sail south and captured the poorly defended city of Gia Định (present-day Ho Chi Minh City). From 1859 during the Siege of Saigon to 1867, French troops expanded their control over all six provinces on the Mekong delta and formed a colony known as Cochinchina.

A few years later, French troops landed in northern Vietnam (which they called Tonkin) and captured Hà Nội twice in 1873 and 1882. The French managed to keep their grip on Tonkin although, twice, their top commanders Francis Garnier and Henri Rivière, were ambushed and killed fighting pirates of the Black Flag Army hired by the mandarins. The Nguyễn dynasty surrendered to France via the Treaty of Huế (1883), marking the colonial era (1883–1954) in the history of Vietnam. France assumed control over the whole of Vietnam after the Tonkin Campaign (1883–1886). French Indochina was formed in October 1887 from Annam (Trung Kỳ, central Vietnam), Tonkin (Bắc Kỳ, northern Vietnam) and Cochinchina (Nam Kỳ, southern Vietnam), with Cambodia and Laos added in 1893. Within French Indochina, Cochinchina had the status of a colony, Annam was nominally a protectorate where the Nguyễn dynasty still ruled, and Tonkin had a French governor with local governments run by Vietnamese officials.

After Vietnam lost Gia Định, the island of Poulo Condor, and three southern provinces to France with the Treaty of Saigon between the Nguyễn dynasty and France in 1862, many resistance movements in the south refused to recognize the treaty and continued to fight the French, some led by former court officers, such as Trương Định, some by farmers and other rural people, such as Nguyễn Trung Trực, who sank the French gunship L'Esperance using guerilla tactics. In the north, most movements were led by former court officers, and fighters were from the rural population. Sentiment against the invasion ran deep in the countryside—well over 90 percent of the population—because the French seized and exported most of the rice, creating widespread malnutrition from the 1880s onward. And, an ancient tradition existed of repelling all invaders. These were two reasons that the vast majority opposed the French invasion.^[191]

The French Invaders seized many farmlands and gave them to Frenchmen and collaborators, who were usually Catholics. By 1898, these seizures created a large class of poor people with little or no land, and a small class of wealthy landowners dependent on the French. In 1905, a Frenchman observed that “Traditional Annamite society, so well organized to satisfy the needs of the people has, in the final analysis, been destroyed by us.” This split in society lasted into the war in the 1960s.

There emerged two parallel movements of modernization. The first was the Đông Du ("Travel to the East") Movement started in 1905 by Phan Bội Châu. Châu's plan was to send Vietnamese students to Japan to learn modern skills, so that in the future they could lead a successful armed revolt against the French. With Prince Cường Để, he started two organizations in Japan: Duy Tân Hội and Việt Nam Công Hiến Hội. Due to French diplomatic pressure, Japan later deported Châu. Phan Châu Trinh, who favored a peaceful, non-violent struggle to gain independence, led a second movement, Duy Tân (Modernization), which stressed education for the masses, modernizing the country, fostering understanding and tolerance between the French and the Vietnamese, and peaceful transitions of power. The early part of the 20th century saw the growing in status of the Romanized Quốc Ngữ alphabet for the Vietnamese language. Vietnamese patriots realized the potential of Quốc Ngữ as a useful tool to quickly reduce illiteracy and to educate the masses. The traditional Chinese scripts or the Nôm script were seen as too cumbersome and too difficult to learn.

As the French suppressed both movements, and after witnessing revolutionaries in action in China and Russia, Vietnamese revolutionaries began to turn to more radical paths. Phan Bội Châu created the Việt Nam Quang Phục Hội in Guangzhou, planning armed resistance against the French. In 1925, French agents captured him in Shanghai and spirited him to Vietnam. Due to his popularity, Châu was spared from execution and placed under house arrest until his death in 1940. In 1927, the Việt Nam Quốc Dân Đảng (Vietnamese Nationalist Party), modeled after the Kuomintang in China, was founded, and the party launched the armed Yên Bái mutiny in 1930 in Tonkin which resulted in its chairman, Nguyễn Thái Học and many other leaders captured and executed by the guillotine.

At the onset of World War I, Vietnam, nominally under the Nguyễn dynasty, was under French protectorate and part of French Indochina. While seeking to maximize the use of Indochina's natural resources and manpower to fight the war, France cracked down all Vietnamese patriotic movements.^[192] The French entry into World War I saw the authorities in Vietnam press-gang thousands of "volunteers" for service in Europe, leading to uprisings in Tonkin and Cochinchina.^[193] Almost 100,000 Vietnamese were conscripts and went to Europe to fight and serve on the French battlefront, or work as laborers.^[194] Several battalions fought and suffered loss of lives at the Somme and Picardy, while others were deployed at Verdun, the Chemin des Dames, and in Champagne.^[195] Vietnamese troops also served in the Balkans and the Middle East. Exposed to new political ideals and returning to a colonial occupation of their own country (by a ruler that many of them had fought and died for), resulted in some sour attitudes. Many of these troops sought out and joined the Vietnamese nationalist movement focused on overthrowing the French.

In 1917 the moderate reformist journalist Phạm Quỳnh had begun publishing the quốc ngữ journal Nam Phong in Hanoi. It addressed the problem of adopting modern Western values without destroying the cultural essence of the Vietnamese nation. By World War I, quốc ngữ had become the vehicle for the dissemination of not only Vietnamese, Hán, and French literary and philosophical classics but also a new body of Vietnamese nationalist literature emphasizing social comment and criticism.

In Cochinchina, patriotic activity manifested itself in the early years of the century by the creation of underground societies. The most important of which was the Thiên Địa Hội (Heaven and Earth Association) whose branches covered many provinces around Saigon. These associations often took the form of political-religious organizations, one of their main activities was to punish traitors in the pay of the French.

In mid-1940, Nazi Germany rapidly defeated the French Third Republic, and the colonial administration of French Indochina (modern-day Vietnam, Laos and Cambodia) passed to the French State (Vichy France). Many concessions were granted to the Nazi-allied Empire of Japan, such as the use of ports, airfields, and railroads.^[196] Japanese troops first entered parts of Indochina in September 1940, and by July 1941 Japan had extended its control over the whole of French Indochina. The United States, concerned by Japanese expansion, started putting embargoes on exports of steel and oil to Japan from July 1940. The desire to escape these embargoes and to become self-sufficient in resources ultimately contributed to Japan's decision to attack on December 7, 1941, the British Empire (in Hong Kong and Malaya) and simultaneously the USA (in the Philippines and at Pearl Harbor, Hawaii). This led to the USA declaring war against Japan on December 8, 1941. The US then joined the side of the British Empire, at war with Germany since 1939, and its existing allies in the fight against the Axis powers.

Indochinese communists had set up a covert headquarters in Cao Bằng Province in 1941, but most of the Vietnamese resistance to Japan, France, or both, including both communist and non-communist groups, remained based over the border, in China. As part of their opposition to Japanese expansion, the Chinese had fostered the formation of a Vietnamese nationalist resistance movement, the Dong Minh Hoi (DMH), in Nanking in 1935/1936; this included communists, but was not controlled by them. This did not provide the desired results, so the Chinese Communist Party sent Ho Chi Minh to Vietnam in 1941 to lead an underground centered on the communist Viet Minh. Ho was the senior Comintern agent in Southeast Asia,^[197] and was in China as an advisor to the Chinese communist armed forces.^[198] This mission was assisted by European intelligence agencies, and later the US Office of Strategic Services (OSS).^[199] Free French intelligence also tried to affect developments in the Vichy-Japanese collaboration. In March 1945, the Japanese imprisoned the French administrators and took direct control of Vietnam until the end of the war.

The August Revolution was a revolution launched by the Việt Minh (League for the Independence of Vietnam) against the Empire of Vietnam and the Empire of Japan in the latter half of August 1945. The Việt Minh, led by the Indochinese Communist Party, was created in 1941 and designed to appeal to a wider population than the communists could command. Within two weeks, forces under the Việt Minh had seized control of most rural villages and cities throughout Northern, Central and Southern Vietnam, including Huế (the then capital of Vietnam), Hanoi and Saigon. The August Revolution sought to create a unified regime for the entire country under the Việt Minh's rule. Việt Minh leader Hồ Chí Minh declared the independence of the Democratic Republic of Vietnam on 2 September 1945. Just as Hồ Chí Minh and the Việt Minh had begun to extend DRV control to all of Vietnam, the attention of his new government was shifting from internal matters to the arrival of Allied troops. At the Potsdam conference in July 1945, the Allies divided Indochina into two zones at the 16th parallel, attaching the southern zone to the Southeast Asia command and leaving the northern part to Chiang Kai-shek's Republic of China to accept the surrender of the Japanese.

French War Crimes

When British forces from the Southeast Asia Command arrived in Saigon on 13 September, they brought along a detachment of French troops. The acquiescence of British occupation forces in the south allowed the French to move rapidly to reassert control over the south of the country, where its economic interests were strongest, DRV authority was weakest and colonial forces were the most deeply entrenched.^[200] Vietnamese civilians were robbed, raped and killed by French soldiers in Saigon when they came back in August 1945.^[201] Vietnamese women were also raped in north Vietnam by the French like in Bảo Hà, Bảo Yên District, Lào Cai province and Phu Lu, which caused 400 Vietnamese who were trained by the French to defect on 20 June 1948. Buddhist statues were looted and Vietnamese were robbed, raped and tortured by the French after the French crushed the Viet Minh in northern Vietnam in 1947–1948 forcing the Viet Minh to flee into Yunnan, China for sanctuary and aid from the Chinese Communists. A French reporter was told "We know what war always is, We understand your soldiers taking our animals, our jewelry, our Buddhas; it is normal. We are resigned to their raping our wives and our daughters; war has always been like that. But we object to being treated in the same way, not only our sons, but ourselves, old men and dignitaries that we are." by Vietnamese village notables. Vietnamese rape victims became "half insane".^[202]

In the north, an uneasy peace had been maintained during the negotiations, in November however, fighting broke out in Haiphong between the Việt Minh government and the French over a conflict of interest in import duty at the port.^{[234 ]}On November 23, 1946, the French fleet bombarded the Vietnamese sections of the city killing 6,000 Vietnamese civilians in one afternoon.^[235] Less than two weeks after the shelling, after receiving pressure from Paris to "teach the Vietnamese a lesson" General Morlière ordered a complete Vietnamese withdrawal from the city, demanding all Viet Minh military elements to be evacuated from Haiphong.^[236] By early December 1946, Haiphong was under complete French military occupation.^[237] The aggressive actions of the French regarding the occupation of Haiphong made it clear in the eyes of the Viet Minh that the French intended on maintaining a colonial presence in Vietnam.^[238] The threat of the French establishing a separate southern state in Vietnam by besieging the city of Hanoi became a top priority for the Viet Minh to counteract.

The final ultimatum to the Vietnamese was issued on December 19, when General Morlière ordered the leading Viet Minh militia, Tu Ve ("self-defence"), to completely disarm. That night, all electricity was turned off in Hanoi and the city was left in complete darkness. The Vietnamese (specifically the Tu Ve militia) attacked the French from within Hanoi with machine guns, artillery, and mortars. Thousands of French soldiers and Vietnamese civilians lost their lives. The French reacted by storming Hanoi the following day, forcing the Vietnamese government to take refuge outside of the city. Ho Chi Minh himself was forced to flee Hanoi for a more remote mountainous area. The attack can be characterized as a preemptive strike against the French after the overtaking of Haiphong endangered Vietnamese claims to Hanoi and all of Vietnam. The uprising in Hanoi escalated the aggression between the French and Viet Minh into the First Indochina War.

The Anti-French Resistance War was fought between France and Việt Minh (Democratic Republic of Vietnam), and their respective allies, from 19 December 1946 until 20 July 1954.^{[203 ]}Việt Minh was led by Võ Nguyên Giáp and Hồ Chí Minh.^[204] Most of the fighting took place in Tonkin in Northern Vietnam, although the conflict engulfed the entire country and also extended into the neighboring French Indochina protectorates of Laos and Cambodia.

The first few years of the war involved a low-level rural insurgency against the French. By 1949 the conflict had turned into a conventional war between two armies equipped with modern weapons, with the French supplied by the United States, and the Việt Minh supplied by the Soviet Union and a newly communist China.^[205] French Union forces included colonial troops from the empire - North Africans; Laotian, Cambodian and Vietnamese ethnic minorities; Sub-Saharan Africans - and professional French troops, European volunteers, and units of the Foreign Legion. It was called the "dirty war" (la sale guerre) by leftists in France.^[206]

The French strategy of inducing the Việt Minh to attack well-defended bases in remote areas at the end of their logistical trails was validated during the Battle of Nà Sản. French efforts were hampered by the limited usefulness of tanks in a forested environment, the lack of a strong air force, and reliance on soldiers from French colonies. The Việt Minh used novel and efficient tactics, including direct artillery fire, convoy ambushes, and anti-aircraft weaponry to impede land and air resupplies together with a strategy based on recruiting a sizable regular army facilitated by large popular support. They used guerrilla warfare doctrine and instruction developed from China, and used war materiel provided by the Soviet Union. This combination proved fatal for the French bases, culminating in a decisive French defeat at the Battle of Dien Bien Phu.^[207]

Both sides committed war crimes during the conflict, including killings of civilians (such as the Mỹ Trạch massacre by French troops), rape and torture.^[208] At the International Geneva Conference on July 21, 1954, the new socialist French government and the Việt Minh made an agreement which gave the Việt Minh control of North Vietnam above the 17th parallel, an agreement that was rejected by the State of Vietnam and the United States. A year later, Bảo Đại would be deposed by his prime minister, Ngô Đình Diệm, creating the Republic of Vietnam (South Vietnam). Soon an insurgency, backed by the communist north, developed against Diệm's anti-communist government. This conflict, known as the Vietnam War, included large U.S. military intervention in support of the South Vietnamese.

The Vietnam War was a conflict in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975.^[209] It was the second of the Indochina Wars and was officially fought between North Vietnam and South Vietnam. The north was supported by the Soviet Union, China, and other communist states, while the south was supported by the United States and other anti-communist allies.^[210] It lasted almost 20 years, with direct U.S. involvement ending in 1973. The conflict also spilled over into neighboring states, exacerbating the Laotian Civil War and the Cambodian Civil War, which ended with all three countries officially becoming communist states by 1976.^[211] Two years after the withdrawal of the last U.S. forces in 1973, Saigon, the capital of South Vietnam, fell to the communists, and the South Vietnamese army surrendered in 1975. In 1976, the government of united Vietnam renamed Saigon as Hồ Chí Minh City in honor of Hồ, who died in 1969.

The war exacted an enormous human cost and left Vietnam devastated, with the total death toll standing at between 966,000 and 3.8 million,^[212] and many thousands more crippled by weapons and substances such as napalm and Agent Orange. The U.S. Air Force destroyed more than 20% of the jungles of South Vietnam and 20–50% of the mangrove forests by spraying over 20 million gallons of toxic herbicides (defoliants) including Agent Orange.^[213] The government of Vietnam says that 4 million of its citizens were exposed to Agent Orange, and as many as 3 million have suffered illnesses because of it; these figures include the children of people who were exposed.^[214] The Red Cross of Vietnam estimates that up to 1 million people are disabled or have health problems due to contaminated Agent Orange.^[215] The end of the Vietnam War would precipitate the Vietnamese boat people and the larger Indochina refugee crisis, which saw millions of refugees leave Indochina, an estimated 250,000 of whom perished at sea.

In the post-1975 period, it was immediately apparent that the effectiveness of Communist Party (CPV) policies did not necessarily extend to the party's peacetime nation-building plans. Having unified North and South politically, the CPV still had to integrate them socially and economically. In this task, CPV policy makers were confronted with the South's resistance to communist transformation, as well as traditional animosities arising from cultural and historical differences between North and South. In the aftermath of the war, under Lê Duẩn's administration, there were no mass executions of South Vietnamese who had collaborated with the U.S. or the Saigon government, confounding Western fears.^[217] However, up to 300,000 South Vietnamese were sent to re-education camps, where many endured torture, starvation, and disease while being forced to perform hard labor.^[218] The New Economic Zones program was implemented by the Vietnamese communist government after the Fall of Saigon. Between 1975 and 1980, more than 1 million northerners migrated to the south and central regions formerly under the Republic of Vietnam. This program, in turn, displaced around 750,000 to over 1 million Southerners from their homes and forcibly relocated them to uninhabited mountainous forested areas.^[219]

Compounding economic difficulties were new military challenges. In the late 1970s, Cambodia under the Khmer Rouge regime started harassing and raiding Vietnamese villages at the common border. By the end of 1978, Vietnamese leaders decided to remove the Khmer Rouge-dominated government of Democratic Kampuchea, perceiving it as being pro-Chinese and hostile towards Vietnam. On 25 December 1978, 150,000 Vietnamese troops invaded Democratic Kampuchea and overran the Kampuchean Revolutionary Army in just two weeks, thereby ending Pol Pot's government, which had been responsible for the deaths of almost a quarter of all Cambodians between 1975 and December 1978 during the Cambodian genocide. Vietnamese military intervention, and the occupying forces' subsequent facilitation of international food aid to mitigate the massive famine, ended the genocide.^[220]

On 8 January 1979 the pro-Vietnamese People's Republic of Kampuchea (PRK) was established in Phnom Penh, marking the beginning of a ten-year Vietnamese occupation. During that period, the Khmer Rouge's Democratic Kampuchea continued to be recognised by the United Nations as the legitimate government of Kampuchea, as several armed resistance groups were formed to fight the Vietnamese occupation. Throughout the conflict, these groups received training in Thailand from the British Army's Special Air Service.^[221] Behind the scenes, Prime Minister Hun Sen of the PRK government approached factions of the Coalition Government of Democratic Kampuchea (CGDK) to begin peace talks. Under diplomatic and economic pressure from the international community, the Vietnamese government implemented a series of economic and foreign policy reforms, and withdrew from Kampuchea in September 1989.

China, now under Deng Xiaoping, was starting the Chinese economic reform and opening trade with the West, in turn, growing increasingly defiant of the Soviet Union. China grew concerned about the strong Soviet influence in Vietnam, fearing that Vietnam could become a pseudo-protectorate of the Soviet Union. Vietnam's claim to be the world's third largest military power following its victory in the Vietnam War also increased Chinese apprehensions. In the Chinese view, Vietnam was pursuing a regional hegemonic policy in an attempt to control Indochina. In July 1978, the Chinese Politburo discussed possible military action against Vietnam in order to disrupt Soviet deployments and, two months later, PLA General Staff recommended punitive actions against Vietnam.^[222]

The major breakdown in the Chinese view of Vietnam occurred in November 1978.^[222] Vietnam joined the CMEA and, on 3 November, the Soviet Union and Vietnam signed a 25-year mutual defense treaty, which made Vietnam the "linchpin" in the Soviet Union's "drive to contain China"^[223] (however, the Soviet Union had shifted from open animosity towards more normalized relations with China soon after).^[224] Vietnam called for a special relationship between the three Indochinese countries, but the Khmer Rouge regime of Democratic Kampuchea rejected the idea.^[222] On 25 December 1978, Vietnam invaded Democratic Kampuchea, overrunning most of the country, deposing the Khmer Rouge, and installing Heng Samrin as the head of the new Cambodian government.^[225] The move antagonized China, which now viewed the Soviet Union as capable of encircling its southern border.^[226]

The reason cited for the attack was to support China's ally, the Khmer Rouge of Cambodia, in addition to the mistreatment of Vietnam's ethnic Chinese minority and the Vietnamese occupation of the Spratly Islands which were claimed by China. To prevent Soviet intervention on Vietnam's behalf, Deng warned Moscow the next day that China was prepared for a full-scale war against the Soviet Union; in preparation for this conflict, China put all of its troops along the Sino-Soviet border on an emergency war alert, set up a new military command in Xinjiang, and even evacuated an estimated 300,000 civilians from the Sino-Soviet border.^[227] In addition, the bulk of China's active forces (as many as one-and-a-half million troops) were stationed along China's border with the Soviet Union.^[228]

In February 1979, Chinese forces launched a surprise invasion of northern Vietnam and quickly captured several cities near the border. On 6 March of that year, China declared that the "gate to Hanoi" had been opened and that its punitive mission had been accomplished. Chinese troops then withdrew from Vietnam. However, Vietnam continued to occupy Cambodia until 1989, which means that China did not achieve its goal of dissuading Vietnam from involvement in Cambodia. But, China's operation at least successfully forced Vietnam to withdraw some units, namely the 2nd Corps, from the invasion forces of Cambodia to reinforce the defense of Hanoi.^[229] The conflict had a lasting impact on the relationship between China and Vietnam, and diplomatic relations between the two countries were not fully restored until 1991. Following the dissolution of the Soviet Union in 1991, the Sino-Vietnamese border was finalized. Although unable to deter Vietnam from ousting Pol Pot from Cambodia, China demonstrated that the Soviet Union, its Cold War communist adversary, was unable to protect its Vietnamese ally.^[230]

After President Bill Clinton visited Vietnam in 2000, a new era of Vietnam began.^[231] Vietnam has become an increasingly attractive destination for economic development. Over time, Vietnam has played an increasingly significant role on the world stage. Its economic reforms have significantly changed Vietnamese society and increased Vietnamese relevance in both Asian and broader international affairs. Also, due to Vietnam's strategic geopolitical position near the intersection of the Pacific and Indian oceans, many world powers have begun to take on a much more favorable stance towards Vietnam.

However, Vietnam also faces disputes, mostly with Cambodia over their shared border, and especially with China, over the South China Sea. In 2016, President Barack Obama became the 3rd U.S. Head of State to visit Vietnam. His historic visit helped to normalize relations with Vietnam. This improvement of U.S-Vietnam relations was further increased by the lifting of a lethal arms embargo, allowing the Vietnamese government to buy lethal weapons and modernize its military.^[232] Vietnam is expected to be a newly industrialized country, and also, a regional power in the future. Vietnam is one of Next Eleven countries.^[233]