History of Thailand

Comparative linguistic research seems to indicate that the Tai peoples were a Proto-Tai–Kadai speaking culture of southern China and dispersed into to mainland Southeast Asia. Many of linguists proposes that Tai–Kadai peoples may genetically connected with Proto-Austronesian speaking peoples, Laurent Sagart (2004) hypothesized that the Tai–Kadai peoples may originally have been of Austronesian descent. Prior to living in mainland China, Tai-Kadai peoples are thought to have migrated from a homeland on the island of Taiwan, where they spoke a dialect of Proto-Austronesian or one of its descendant languages.^[19] Unlike the Malayo-Polynesian group who later sailed south to the Philippines and other parts of maritime Southeast Asia, the ancestors of the modern Tai-Kadai people sailed west to mainland China and possibly traveled along the Pearl River, where their language greatly changed from other Austronesian languages under the influence of Sino-Tibetan and Hmong–Mien language infusion.^[20] Aside from linguistic evidence, the connection between Austronesian and Tai-Kadai can also be found in some common cultural practices. Roger Blench (2008) demonstrates that dental evulsion, face tattooing, teeth blackening and snake cults are shared between the Taiwanese Austronesians and the Tai-Kadai peoples of Southern China.^[21]

James R. Chamberlain proposes that the Tai-Kadai (Kra-Dai) language family was formed as early as the 12th century BCE in the middle of the Yangtze basin, coinciding roughly with the establishment of the Chu state and the beginning of the Zhou dynasty. Following the southward migrations of Kra and Hlai (Rei/Li) peoples around the 8th century BCE, the Yue (Be-Tai people) started to break away and move to the east coast in the present-day Zhejiang province, in the 6th century BCE, forming the state of Yue and conquering the state of Wu shortly thereafter. According to Chamberlain, Yue people (Be-Tai) began to migrate southwards along the east coast of China to what are now Guangxi, Guizhou and northern Vietnam, after Yue was conquered by Chu around 333 BCE. There the Yue (Be-Tai) formed the Luo Yue, which moved into Lingnan and Annam and then westward into northeastern Laos and Si p Song Chau Tai, and later became the Central-Southwestern Tai, followed by the Xi Ou, which became the Northern Tai.^[22]

The oldest known records of a political entity in Indochina are attributed to Funan – centered in the Mekong Delta and comprising territories inside modern day Thailand.^[4] Chinese annals confirm Funan's existence as early as the first century CE. Archaeological documentation implies an extensive human settlement history since the fourth century BCE.^[5] Though regarded by Chinese authors as a single unified polity, some modern scholars suspect that Funan may have been a collection of city-states that sometimes were at war with one another and at other times constituted a political unity.^[6] From archaeological evidence, which includes Roman, Chinese, and Indian goods excavated at the ancient mercantile centre of Óc Eo in southern Vietnam, it is known that Funan must have been a powerful trading state.^[7] Excavations at Angkor Borei in southern Cambodia have likewise delivered evidence of an important settlement. Since Óc Eo was linked to a port on the coast and to Angkor Borei by a system of canals, it is possible that all of these locations together constituted the heartland of Funan.

Funan was the name given by Chinese cartographers, geographers and writers to an ancient Indianized state—or, rather a loose network of states (Mandala)^[8] — located in mainland Southeast Asia centered on the Mekong Delta that existed from the first to sixth century CE. The name is found in Chinese historical texts describing the kingdom, and the most extensive descriptions are largely based on the report of two Chinese diplomats, Kang Tai and Zhu Ying, representing the Eastern Wu dynasty who sojourned in Funan in the mid-3rd century CE.^[9]

Like the very name of the kingdom, the ethno-linguistic nature of the people is the subject of much discussion among specialists. The leading hypotheses are that the Funanese were mostly Mon–Khmer, or that they were mostly Austronesian, or that they constituted a multi-ethnic society. The available evidence is inconclusive on this issue. Michael Vickery has said that, even though identification of the language of Funan is not possible, the evidence strongly suggests that the population was Khmer.^[10]

The area of Dvaravati (what is now Thailand) was first inhabited by Mon people who had arrived and appeared centuries earlier. The foundations of Buddhism in central Southeast Asia were laid between the 6th and 9th centuries when a Theravada Buddhist culture linked to the Mon people developed in central and northeastern Thailand. Theravadin Buddhists believe that Enlightenment can be obtained only by one living the life of a monk (and not by a layman). Unlike Mahayana Buddhists, who admit the texts of numerous Buddhas and Bodhisattvas into canon, Theravadans venerate only the Buddha Gautama, the founder of the religion. The Mon Buddhist kingdoms that rose in what are now parts of Laos and Central Plain of Thailand were collectively called Dvaravati. Around the tenth century, the city-states of Dvaravati merged into two mandalas, the Lavo (modern Lopburi) and the Suvarnabhumi (modern Suphan Buri).

The Chao Phraya River in what is now central Thailand had once been the home of the Mon Dvaravati culture, which prevailed from the seventh century to the tenth century.^[11] Samuel Beal discovered the polity among the Chinese writings on Southeast Asia as "Duoluobodi". During the early 20th century archaeological excavations led by George Coedès found Nakhon Pathom Province to be a centre of Dvaravati culture. The culture of Dvaravati was based around moated cities, the earliest of which appears to be U Thong in what is now Suphan Buri Province. Other key sites include Nakhon Pathom, Phong Tuk, Si Thep, Khu Bua and Si Mahosot, amongst others.^[12] The inscriptions of Dvaravati were in Sanskrit and Mon using the script derived from the Pallava alphabet of the South Indian Pallava dynasty.

Dvaravati was a network of city-states paying tribute to more powerful ones according to the mandala political model. Dvaravati culture expanded into Isan as well as south as far as the Kra Isthmus. The culture lost power around the tenth century when they submitted to the more unified Lavo-Khmer polity. Around the tenth century, the city-states of Dvaravati merged into two mandalas, the Lavo (modern Lopburi) and the Suvarnabhumi (modern Suphan Buri).

Haripuñjaya^[13] was a Mon kingdom in what is now Northern Thailand, existing from the 7th or 8th to 13th century CE. At that time, most of what is now central Thailand was under the rule of various Mon city states, known collectively as the Dvaravati kingdom. Its capital was at Lamphun, which at the time was also called Haripuñjaya.^[14] The chronicles say that the Khmer unsuccessfully besieged Haripuñjaya several times during the 11th century. It is not clear if the chronicles describe actual or legendary events, but the other Dvaravati Mon kingdoms did in fact fall to the Khmers at this time. The early 13th century was a golden time for Haripuñjaya, as the chronicles talk only about religious activities or constructing buildings, not about wars. Nevertheless, Haripuñjaya was besieged in 1292 by the Tai Yuan king Mangrai, who incorporated it into his Lan Na ("One Million Rice Fields") kingdom. The plan set up by Mangrai to overpower Haripuñjaya began by dispatching Ai Fa on an espionage mission to create chaos in Haripuñjaya. Ai Fa managed to spread discontent among the population, which weakened Haripuñjaya and made it possible for Mangrai to take the kingdom over.^[15]

According to the Northern Thai Chronicles, Lavo was founded by Phraya Kalavarnadishraj, who came from Takkasila in 648 CE.^[16] According to Thai records, Phraya Kakabatr from Takkasila (it is assumed that the city was Tak or Nakhon Chai Si)^[17] set the new era, Chula Sakarat in 638 CE, which was the era used by the Siamese and the Burmese until the 19th century. His son, Phraya Kalavarnadishraj founded the city a decade later.

King Kalavarnadishraj used the name "Lavo" as the name of the kingdom, which came from the Hindu name "Lavapura", meaning "city of Lava", in reference to the ancient South Asian city of Lavapuri (present-day Lahore).^[18] Around the late 7th century, Lavo expanded to the north. Few records are found concerning the nature of the Lavo kingdom. Most of what we know about Lavo is from archaeological evidence.

Around the tenth century, the city-states of Dvaravati merged into two mandalas, the Lavo (modern Lopburi) and the Suvarnabhumi (modern Suphan Buri). According to a legend in the Northern Chronicles, in 903, a king of Tambralinga invaded and took Lavo and installed a Malay prince on the Lavo throne. The Malay prince was married to a Khmer princess who had fled an Angkorian dynastic bloodbath. The son of the couple contested the Khmer throne and became Suryavarman I, thus bringing Lavo under Khmer domination through the marital union. Suryavarman I also expanded into the Khorat Plateau (later styled "Isan"), constructing many temples.

Suryavarman, however, had no male heirs and again Lavo was independent. After the death of King Narai of Lavo, however, Lavo was plunged into bloody civil war and the Khmer under Suryavarman II took advantage by invading Lavo and installing his son as the King of Lavo. The repeated but discontinued Khmer domination eventually Khmerized Lavo. Lavo was transformed from a Theravadin Mon Dvaravati city into a Hindu Khmer one. Lavo became the entrepôt of Khmer culture and power of the Chao Phraya river basin. The bas-relief at Angkor Wat shows a Lavo army as one of the subordinates to Angkor. One interesting note is that a Tai army was shown as a part of Lavo army, a century before the establishment of the "Sukhothai Kingdom".

The most recent and accurate theory about the origin of the Tai people stipulates that Guangxi in China is really the Tai motherland instead of Yunnan. A large number of Tai people known as the Zhuang still live in Guangxi today. Around 700 CE, Tai people who did not come under Chinese influence settled in what is now Điện Biên Phủ in modern Vietnam according to the Khun Borom legend. Based on layers of Chinese loanwords in proto-Southwestern Tai and other historical evidence, Pittayawat Pittayaporn (2014) proposed that this migration must have taken place sometime between the eighth–10th centuries.^[23] Tai speaking tribes migrated southwestward along the rivers and over the lower passes into Southeast Asia, perhaps prompted by the Chinese expansion and suppression.

The Simhanavati legend tells us that a Tai chief named Simhanavati drove out the native Wa people and founded the city of Chiang Saen around 800 CE. For the first time, the Tai people made contact with the Theravadin Buddhist kingdoms of Southeast Asia. Through Hariphunchai, the Tais of Chiang Saen embraced Theravada Buddhism and Sanskrit royal names. Wat Phrathat Doi Tong, constructed around 850, signified the piety of Tai people on the Theravada Buddhism. Around 900, major wars were fought between Chiang Saen and Hariphunchaya. Mon forces captured Chiang Saen and its king fled. In 937, Prince Prom the Great took Chiang Saen back from the Mon and inflicted severe defeats on Hariphunchaya. By 1100 CE, the Tai had established themselves as Po Khuns (ruling fathers) at Nan, Phrae, Songkwae, Sawankhalok, and Chakangrao on the upper Chao Phraya River. These southern Tai princes faced Khmer influence from the Lavo Kingdom. Some of them became subordinates to it.

The Khmer Empire was a Hindu-Buddhist empire in Southeast Asia, centered around hydraulic cities in what is now northern Cambodia. Known as Kambuja by its inhabitants, it grew out of the former civilisation of Chenla and lasted from 802 to 1431. The Khmer Empire ruled or vassalised most of mainland Southeast Asia^[24] and stretched as far north as southern China.^[25] At its peak, the Empire was larger than the Byzantine Empire, which existed around the same time.^[26]

The beginning of the Khmer Empire is conventionally dated to 802, when Khmer prince Jayavarman II declared himself chakravartin in the Phnom Kulen mountains. Although the end of the Khmer Empire has traditionally been marked with the Fall of Angkor to the Siamese Ayutthaya Kingdom in 1431, the reasons for the empire's collapse is still debated amongst scholars.^[27] Researchers have determined that a period of strong monsoon rains was followed by a severe drought in the region, which caused damage to the empire's hydraulic infrastructure. Variability between droughts and flooding was also a problem, which may have caused residents to migrate southward and away from the empire's major cities.^[28]

Thai city-states gradually became independent of the weakened Khmer Empire. Sukhothai was originally a trade center in Lavo—itself under the suzerainty of the Khmer Empire—when Central Thai people led by Pho Khun Bang Klang Hao, a local leader, revolted and gained their independence. Bang Klang Hao took the regnal name of Si Inthrathit and became the first monarch of the Phra Ruang dynasty. The kingdom was centralized and expanded to its greatest extent during the reign of Ram Khamhaeng the Great (1279–1298), who some historians considered to have introduced Theravada Buddhism and the initial Thai script to the kingdom. Ram Khamhaeng also initiated relations with Yuan China, through which the kingdom developed the techniques to produce and export ceramics like sangkhalok ware.

After the reign of Ram Khamhaeng, the kingdom fell into decline. In 1349, during the reign of Li Thai (Maha Thammaracha I), Sukhothai was invaded by the Ayutthaya Kingdom, a neighboring Thai polity. It remained a tributary state of Ayutthaya until it was annexed by the kingdom in 1438 after the death of Borommapan. Despite this, the Sukhothai nobility continued to influence the Ayutthaya monarchy in centuries after through the Sukhothai dynasty. Sukhothai is traditionally known as "the first Thai kingdom" in Thai historiography, but current historical consensus agrees that the history of the Thai people began much earlier.

Mangrai, the 25th king of Ngoenyang (modern Chiang Saen) of the Lavachakkaraj dynasty, whose mother was a princess of a kingdom in Sipsongpanna ("the twelve nations"), centralized the mueangs of Ngoenyang into a unified kingdom or mandala and allied with the neighboring Phayao Kingdom. In 1262, Mangrai moved the capital from Ngoenyang to the newly founded Chiang Rai — naming the city after himself. Mangrai then expanded to the south and subjugated the Mon kingdom of Hariphunchai (centered on modern Lamphun) in 1281. Mangrai moved the capital several times. Leaving Lamphun due to heavy flooding, he drifted until settling at and building Wiang Kum Kam in 1286/7, staying there until 1292 at which time he relocated to what would become Chiang Mai. He founded Chiang Mai in 1296, expanding it to become the capital of Lan Na.

The cultural development of the Northern Thai people had begun long before as successive kingdoms preceded Lan Na. As a continuation of the kingdom of Ngoenyang, Lan Na emerged strong enough in the 15th century to rival the Ayutthaya Kingdom, with whom wars were fought. However, the Lan Na Kingdom was weakened and became a tributary state of the Taungoo Dynasty in 1558. Lan Na was ruled by successive vassal kings, though some enjoyed autonomy. The Burmese rule gradually withdrew but then resumed as the new Konbaung Dynasty expanded its influence. In 1775, Lan Na chiefs left the Burmese control to join Siam, leading to the Burmese–Siamese War (1775–76). Following the retreat of the Burmese force, Burmese control over Lan Na came to the end. Siam, under King Taksin of the Thonburi Kingdom, gained control of Lan Na in 1776. From then on, Lan Na became a tributary state of Siam under the succeeding Chakri Dynasty.

Throughout the latter half of the 1800s, the Siamese state dismantled Lan Na independence, absorbing it into the emerging Siamese nation-state.^[29] Beginning in 1874, the Siamese state reorganized Lan Na Kingdom as Monthon Phayap, brought under the direct control of Siam.^[30] The Lan Na Kingdom effectively became centrally administered from through the Siamese thesaphiban governance system instituted in 1899.^[31] By 1909, Lan Na Kingdom no longer existed formally as an independent state, as Siam finalized the demarcation of its borders with the British and French.^[32]

The Ayutthaya Kingdom emerged from the mandala/merger of three maritime city-states on the Lower Chao Phraya Valley in the late 13th and 14th centuries (Lopburi, Suphanburi, and Ayutthaya).^[33] The early kingdom was a maritime confederation, oriented to post-Srivijaya Maritime Southeast Asia, conducting raids and tribute from these maritime states.

The first ruler of the Kingdom of Ayutthaya, King Uthong (r. 1351–1369), made two important contributions to Thai history: the establishment and promotion of Theravada Buddhism as the official religion to differentiate his kingdom from the neighbouring Hindu kingdom of Angkor and the compilation of the Dharmaśāstra, a legal code based on Hindu sources and traditional Thai custom. The Dharmaśāstra remained a tool of Thai law until late in the 19th century.

In 1511 Duke Afonso de Albuquerque dispatched Duarte Fernandes as an envoy to the Ayutthaya Kingdom, known then to Europeans as the "Kingdom of Siam". This contact with the West during the 16th century led to a period of economic growth as lucrative trade routes were established. Ayutthaya became one of the most prosperous cities in Southeast Asia. According to George Modelski, Ayutthaya is estimated to have been the largest city in the world in 1700 CE, with a population around one million.^[34] Trade flourished, with the Dutch and Portuguese among the most active foreigners in the kingdom, together with the Chinese and Malayans. Even Luzones merchants and warriors from Luzon, Philippines were also present.^[35] Philippines-Thailand relations already had precursors in that, Thailand often exported ceramics to several Filipino states as evidenced that when the Magellan expedition landed at the Cebu Rajahnate, they noted a Thai embassy to the king, Rajah Humabon.^[36] When the Spanish colonized the Philippines via Latin America, Spaniards and Mexicans joined the Filipinos in trading at Thailand.

The reign of Narai (r. 1657–1688) was known for Persian and later, European, influence and the sending of the 1686 Siamese embassy to the French court of King Louis XIV. The Late Ayutthaya Period saw the departure of the French and English but growing prominence of the Chinese. The period was described as a "golden age" of Siamese culture and saw the rise in Chinese trade and the introduction of capitalism into Siam,^[37] a development that would continue to expand in the centuries following the fall of Ayutthaya.^[38] The Ayutthaya period was also considered as "a golden age of medicine in Thailand" due to progress in the field of medicine at that time.^[39]

Ayutthaya's failure to create a peaceful order of succession and the introduction of capitalism undermined the traditional organization of its elite and the old bonds of labor control which formed the military and government organization of the kingdom. In the mid-18th century, the Burmese Konbaung dynasty invaded Ayutthaya in 1759–1760 and 1765–1767. In April 1767, after a 14-month siege, the city of Ayutthaya fell to besieging Burmese forces and was completely destroyed, thereby ending the 417-year-old Ayutthaya Kingdom. Siam, however, quickly recovered from the collapse and the seat of Siamese authority was moved to Thonburi-Bangkok within the next 15 years.^[40]

The Burmese–Siamese War (1547–1549), also known as the Shwehti War, was the first war fought between the Toungoo dynasty of Burma and the Ayutthaya Kingdom of Siam, and the first of the Burmese–Siamese wars that would continue until the middle of the 19th century. The war is notable for the introduction of early modern warfare to the region. It is also notable in Thai history for the death in battle of Siamese Queen Suriyothai on her war elephant; the conflict is often referred to in Thailand as the War that Led to the Loss of Queen Suriyothai.

The casus belli have been stated as a Burmese attempt to expand their territory eastwards after a political crisis in Ayutthaya^[41] as well as an attempt to stop Siamese incursions into the upper Tenasserim coast.^[42] The war, according to the Burmese, began in January 1547 when Siamese forces conquered the frontier town of Tavoy (Dawei). Later in the year, the Burmese forces led by Gen. Saw Lagun Ein retook the Upper Tenasserim coast down to Tavoy. Next year, in October 1548, three Burmese armies led by King Tabinshwehti and his deputy Bayinnaung invaded Siam through the Three Pagodas Pass. The Burmese forces penetrated up to the capital city of Ayutthaya but could not take the heavily fortified city. One month into the siege, Siamese counterattacks broke the siege, and drove back the invasion force. But the Burmese negotiated a safe retreat in exchange for the return of two important Siamese nobles (the heir apparent Prince Ramesuan, and Prince Thammaracha of Phitsanulok) whom they had captured.

Following the 1547–49 war with the Toungoo, Ayutthaya king Maha Chakkraphat built up his capital city's defenses in preparation for a later war with the Burmese. The 1547–49 war ended in a Siamese defensive victory and preserved Siamese independence. However, Bayinnaung's territorial ambitions prompted Chakkraphat to prepare for another invasion. These preparations included a census that prepared all able men to go to war. Arms and livestock were taken by the government in preparation for a large-scale war effort, and seven white elephants were captured by Chakkraphat for good luck. News of the Ayutthayan king's preparation spread quickly, eventually reaching the Burmese.

Bayinnaung succeeded in taking the city of Chiang Mai in the nearby Lan Na kingdom in 1556. Subsequent efforts left most of northern Siam under Burmese control. This left Chakkraphat's kingdom in a precarious position, faced with enemy territory to the north and the west. Bayinnaung subsequently demanded two of King Chakkraphat's white elephants as tribute to the rising Toungoo Dynasty. Chakkraphat refused, leading to Burma's second invasion of the Ayutthaya Kingdom.

The Bayinnaung armies marched down to Ayutthaya. There, they were kept at bay for weeks by the Siamese fort, aided by three Portuguese warships and artillery batteries at the harbor. The invaders finally captured the Portuguese ships and batteries on 7 February 1564, after which the fort promptly fell.^[43] With a now 60,000 strong force combined with the Phitsanulok army, Bayinnaung reached Ayutthaya's city walls, heavily bombarding the city. Although superior in strength, the Burmese were not able to capture Ayutthaya, but demanded that the Siamese king come out of the city under a flag of truce for peace negotiations. Seeing that his citizens could not take the siege much longer, Chakkraphat negotiated peace, but at a high price.

In exchange for the retreat of the Burmese army, Bayinnaung took Prince Ramesuan (Chakkraphat's son), Phraya Chakri, and Phraya Sunthorn Songkhram back with him to Burma as a hostage, and four Siamese white elephants. Mahathamraja, although a betrayer, was to be left as ruler of Phitsanulok and viceroy of Siam. The Ayutthaya Kingdom became a vassal of the Toungoo Dynasty, required to give thirty elephants and three hundred catties of silver to the Burmese yearly.

In 1581, King Bayinnaung of the Toungoo dynasty died, and was succeeded by his son Nanda Bayin. Nanda's uncle Viceroy Thado Minsaw of Ava then rebelled in 1583, forcing Nanda Bayin to call upon the viceroys of Prome, Taungoo, Chiang Mai, Vientiane, and Ayutthaya for assistance in suppressing the rebellion. After Ava fell quickly, the Siamese army withdrew to Martaban (Mottama), and declared independence on 3 May 1584.

Nanda launched four unsuccessful campaigns against Ayuthayya. On the final campaign, the Burmese launched invasion army of 24,000 on 4 November 1592. After seven weeks, the army fought its way to Suphan Buri, a town just to the west of Ayutthaya.^[44] Here Burmese chronicle and Siamese chronicle narratives give different accounts. Burmese chronicles say that a battle took place on 8 January 1593, in which Mingyi Swa and Naresuan fought on their war elephants. In the battle, Mingyi Swa was felled by a gunshot, after which the Burmese army retreated. According to Siamese chronicles, the battle took place on 18 January 1593. Like in the Burmese chronicles, the battle started out between the two forces but the Siamese chronicles say that midway through the battle, the two sides agreed to decide the outcome by having a duel between Mingyi Swa and Naresuan on their elephants, and that Mingyi Swa was cut down by Naresuan.^[45] After this, the Burmese forces retreated, suffering heavy casualties along the way as the Siamese chased and destroyed their army. This was the last of the campaigns by Nanda Bayin to invade Siam.

The Nandric War led Ayutthaya out of Burmese vassalship. and freed Siam from further Burmese domination for 174 years.

King Narai the Great was the 27th monarch of Ayutthaya Kingdom, the 4th and last monarch of the Prasat Thong dynasty. He was the king of Ayutthaya Kingdom from 1656 to 1688 and arguably the most famous king of the Prasat Thong dynasty. His reign was the most prosperous during the Ayutthaya period and saw the great commercial and diplomatic activities with foreign nations including the Middle East and the West. During the later years of his reign, Narai gave his favorite – the Greek adventurer Constantine Phaulkon – so much power that Phaulkon technically became the chancellor of the state. Through the arrangements of Phaulkon, the Siamese kingdom came into close diplomatic relations with the court of Louis XIV and French soldiers and missionaries filled the Siamese aristocracy and defense. The dominance of French officials led to frictions between them and the native mandarins and led to the turbulent revolution of 1688 towards the end of his reign.

The Siamese revolution of 1688 was a major popular uprising in the Siamese Ayutthaya Kingdom (modern Thailand) which led to the overthrow of the pro-French Siamese king Narai. Phetracha, previously one of Narai's trusted military advisors, took advantage of the elderly Narai's illness, and killed Narai's Christian heir, along with a number of missionaries and Narai's influential foreign minister, the Greek adventurer Constantine Phaulkon. Phetracha then married Narai's daughter, took the throne, and pursued a policy of ousting French influence and military forces from Siam. One of the most prominent battles was 1688's Siege of Bangkok, when tens of thousands of Siamese forces spent four months besieging a French fortress within the city. As a consequence of the revolution, Siam severed significant ties with the Western world, with the exception of the Dutch East India Company, until the 19th century.

In 1714, King Ang Tham or Thommo Reachea of Cambodia was driven off by Kaev Hua, who was supported by the Vietnamese Nguyen Lord. Ang Tham took refuge in Ayutthaya where King Thaisa granted him a place to reside. Three years later, in 1717, the Siamese king sent armies and navy to reclaim Cambodia for Ang Tham, leading to the Siamese–Vietnamese War (1717). Two large Siamese forces invade Cambodia in an effort to help Prea Srey Thomea regain the throne. One Siamese army is badly beaten by the Cambodians and their Vietnamese allies at the Battle of Bantea Meas. The Second Siamese army captures the Cambodian capital of Udong where the Vietnamese supported Cambodian king switches allegiance to Siam. Vietnam loses the suzerainty of Cambodia but annexes several border provinces of Cambodia.

The Burmese–Siamese War (1759–1760) was the first military conflict between the Konbaung dynasty of Burma (Myanmar) and the Ban Phlu Luang Dynasty of the Ayutthaya Kingdom of Siam. It reignited the centuries-long conflict between the two Southeast Asian states that would last for another century. The Burmese were "on the brink of victory" when they suddenly withdrew from their siege of Ayutthaya because their king Alaungpaya had fallen ill.^[46] He died three weeks later, ending the war.

The casus belli were over the control of the Tenasserim coast and its trade,^[47] and the Siamese support for ethnic Mon rebels of the fallen Restored Hanthawaddy Kingdom.^[46] The newly founded Konbaung Dynasty had wanted to reestablish Burmese authority in the upper Tenasserim coast (present-day Mon State) where the Siamese had provided support to the Mon rebels and deployed their troops. The Siamese had refused Burmese demands to hand over the Mon leaders or to stop their intrusions into what the Burmese considered their territory.^[48]

The war began in December 1759 when 40,000 Burmese troops led by Alaungpaya and his son Hsinbyushin invaded down the Tenasserim coast from Martaban. Their battle plan was to go around the heavily defended Siamese positions along shorter, more direct invasion routes. The invasion force overran relatively thin Siamese defenses in the coast, crossed the Tenasserim Hills to the shore of the Gulf of Siam, and turned north towards Ayutthaya. Taken by surprise, the Siamese scrambled to meet the Burmese in their south, and put up spirited defensive stands en route to Ayutthaya. But battle-hardened Burmese forces overcame numerically superior Siamese defenses and reached the outskirts of Siamese capital on 11 April 1760. But only five days into the siege, the Burmese king suddenly fell ill and the Burmese command decided to withdraw. An effective rearguard operation by General Minkhaung Nawrahta allowed for an orderly withdrawal.^[49]

The war was inconclusive. While the Burmese regained control of the upper coast down to the Tavoy, they had not eliminated the threat to their hold on the peripheral regions, which remained tenuous. They were forced to deal with Siamese-supported ethnic rebellions in the coast (1762, 1764) as well as in Lan Na (1761–1763).

The Burmese–Siamese War (1765–1767), also known as the fall of Ayoudhia was the second military conflict between the Konbaung dynasty of Burma (Myanmar) and the Ban Phlu Luang dynasty of the Ayutthaya Kingdom of Siam, and the war that ended the 417-year-old Ayutthaya Kingdom.^[50] This war was the continuation of the 1759–60 war. The casus belli of this war was also the control of the Tenasserim coast and its trade, and Siamese support for rebels in the Burmese border regions.^[51] The war began in August 1765 when a 20,000-strong northern Burmese army invaded northern Siam, and was joined by three southern armies of over 20,000 in October, in a pincer movement on Ayutthaya. By late-January 1766, the Burmese armies had overcome numerically superior but poorly coordinated Siamese defenses, and converged before the Siamese capital.^[50]

The siege of Ayutthaya began during the first Qing invasion of Burma. The Siamese believed that if they could hold out until the rainy season, the seasonal flooding of the Siamese central plain would force a retreat. But King Hsinbyushin of Burma believed that the Chinese war was a minor border dispute, and continued the siege. During the rainy season of 1766 (June–October), the battle moved to the waters of the flooded plain but failed to change the status quo.^[50] When the dry season came, the Chinese launched a much larger invasion but Hsinbyushin still refused to recall the troops. In March 1767, King Ekkathat of Siam offered to become a tributary but the Burmese demanded unconditional surrender.^[52] On 7 April 1767, the Burmese sacked the starving city for the second time in its history, committing atrocities that have left a major black mark on Burmese-Thai relations to the present day. Thousands of Siamese captives were relocated to Burma.

The Burmese occupation was short-lived. In November 1767, the Chinese again invaded with their largest force yet, finally convincing Hsinbyushin to withdraw his forces from Siam. In the ensuing civil war in Siam, the Siamese state of Thonburi, led by Taksin, had emerged victorious, defeating all other breakaway Siamese states and eliminating all threats to his new rule by 1771.^[53] The Burmese, all the while, were preoccupied defeating a fourth Chinese invasion of Burma by December 1769.

The Thonburi Kingdom was a major Siamese kingdom which existed in Southeast Asia from 1767 to 1782, centered around the city of Thonburi, in Siam or present-day Thailand. The kingdom was founded by Taksin the Great, who reunited Siam following the collapse of the Ayutthaya Kingdom, which saw the country separate into five warring regional states. The Thonburi Kingdom oversaw the rapid reunification and reestablishment of Siam as a preeminient military power within mainland Southeast Asia, overseeing the country's expansion to its greatest territorial extent up to that point in its history, incorporating Lan Na, the Laotian kingdoms (Luang Phrabang, Vientiane, Champasak), and Cambodia under the Siamese sphere of influence.^[54]

In the Thonburi period, the beginning of the Chinese mass immigration fell to Siam. Through the availability of Chinese workers, trade, agriculture and craftsmen flourished. However, the first Chinese rebellions had to be suppressed. However, later due to stress and many factors, King Taksin supposedly suffered mental breakdowns. After a coup d'état removing Taksin from power, stability was restored by General Chao Phraya Chakri, who subsequently founded the Rattanakosin Kingdom, the fourth and present ruling kingdom of Thailand.

In 1769, King Taksin of Thonburi sent a letter to the pro-Vietnamese King Ang Ton of Cambodia, urging Cambodia to resume sending the submissive tribute of golden and silver trees to Siam. Ang Ton refused on the grounds that Taksin was a Chinese usurper. Taksin was angered and ordered the invasion to subjugate Cambodia and install the pro-Siamese Ang Non on the Cambodian throne. King Taksin 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.

After the Mon Rebellion of 1774 and the successful Siamese capture of Burmese-held Chiang Mai in 1775, King Hsinbyushin assigned Maha Thiha Thura the general of Sino-Burmese War to conduct a large-scale invasion of Northern Siam in late 1775 in order to curb the rising Siamese power under King Taksin of Thonburi. As the Burmese forces outnumbered the Siamese, the three-month siege of Phitsanulok was the main battle of the war. Defenders of Phitsanulok, led by Chaophraya Chakri and Chaophraya Surasi, resisted the Burmese. The war reached stalemate until Maha Thiha Thura decided to disrupt the Siamese supply line, leading to the Fall of Phitsanulok in March 1776. The Burmese gained upper hand but the untimely demise of King Hsinbyushin ruined the Burmese operations as the new Burmese king ordered the withdrawal of all troops back to Ava. The premature exit of Maha Thiha Thura from war in 1776 left the remaining Burmese troops in Siam to retreat in disarray. King Taksin then took this opportunity to send his generals to harass the retreating Burmese. The Burmese forces had completely left Siam by September 1776 and the war was over.

The Maha Thiha Thira's Invasion of Siam in 1775–1776 was the largest Burmese-Siamese war in the Thonburi Period. The war (and subsequent wars) entirely wrecked and depopulated large sections of Siam for decades to come, some regions would not be entirely repopulated until the late 19th century.^[55]

The Rattanakosin Kingdom was founded in 1782 with the establishment of Rattanakosin (Bangkok), which replaced the city of Thonburi as the capital of Siam. The maximum zone of influence of Rattanakosin included the vassal states of Cambodia, Laos, Shan States, and the northern Malay states. The kingdom was founded by Rama I of the Chakri Dynasty. The first half of this period was characterized by the consolidation of Siamese power in the center of Mainland Southeast Asia and was punctuated by contests and wars for regional supremacy with rival powers Burma and Vietnam.^[56] The second period was one of engagements with the colonial powers of Britain and France in which Siam remained the only Southeast Asian state to maintain its independence.^[57]

Internally the kingdom developed into a centralized, absolutist, nation state with borders defined by interactions with Western powers. The period was marked by the increased centralization of the monarch's powers, the abolition of labor control, the transition to an agrarian economy, the expansion of control over distant tributary states, the creation of a monolithic national identity, and the emergence of an urban middle class. However, the failure to implement democratic reforms culminated in the Siamese revolution of 1932 and the establishment of a constitutional monarchy.

The Burmese–Siamese War (1785–1786), known as the Nine Armies' Wars in Siamese history because the Burmese came in nine armies, was the first war^[58] between the Konbaung dynasty of Burma and the Siamese Rattanakosin Kingdom of the Chakri dynasty.

King Bodawpaya of Burma pursued an ambitious campaign to expand his dominions into Siam. In 1785, three years after the foundation of Bangkok as the new royal seat and the Chakri dynasty, King Bodawpaya of Burma marched massive armies with total number of 144,000 to invade Siam in nine armies through five directions^[58] including Kanchanaburi, Ratchaburi, Lanna, Tak, Thalang (Phuket), and the southern Malay Peninsula. However, the overstretched armies and provision shortages deemed the Burmese campaign failed. The Siamese under King Rama I and his younger brother Prince Maha Sura Singhanat successfully warded off Burmese invasions. By early 1786, the Burmese had largely retreated.

After the truce during the rainy season, King Bodawpaya resumed his campaign in late 1786. King Bodawpaya sent his son Prince Thado Minsaw to concentrate his forces on Kanchanaburi in only a single direction to invade Siam. The Siamese met the Burmese at Tha Dindaeng, hence the term "Tha Din Daeng campaign". The Burmese were again defeated and Siam managed to defend its western border. These two failed invasions ultimately turned out to be the last full-scale invasion of Siam by Burma.

Kingdom of Rattanatingsa or Kingdom of Chiang Mai was the vassal state of the Siamese Rattanakosin Kingdom in the 18th and 19th century before being annexed according to the centralization policies of Chulalongkorn in 1899. The kingdom was a successor of the medieval Lanna kingdom, which had been under Burmese rule for two centuries until it was captured by Siamese forces under Taksin of Thonburi in 1774. It was ruled by the Thipchak Dynasty and came under Thonburi tributary.

During Rama II's reign, the kingdom saw a cultural renaissance after the massive wars that plagued his predecessor's reign; particularly in the fields of arts and literature. Poets employed by Rama II included Sunthorn Phu the drunken writer (Phra Aphai Mani) and Narin Dhibet (Nirat Narin). Foreign relations were initially dominated by relations with the neighbouring states, while those with European colonial powers started to enter in the background. In Cambodia and Laos, Vietnam gained the supremacy, a fact which Rama II initially accepted. When a rebellion broke out in Vietnam under Rama III in 1833–34, he tried to subdue the Vietnamese militarily, but this led to a costly defeat for the Siamese troops. In the 1840s, however, the Khmer themselves succeeded in expelling the Vietnamese, which subsequently led to the greater influence of Siam in Cambodia. At the same time, Siam kept sending tribute to Qing China. Under Rama II and Rama III, culture, dance, poetry and above all the theatre reached a climax. The temple Wat Pho was built by Rama III, known as the first university of the country.

The reign of Rama III. was finally marked by a division of the aristocracy with regard to foreign policy. A small group of advocates of the takeover of Western technologies and other achievements were opposed by conservative circles, which proposed a stronger isolation instead. Since the kings Rama II and Rama III, the conservative-religious circles largely stuck with their isolationist tendency. The death of Rama III in 1851 also signified the end of the old traditional Siamese monarchy: there were already clear signs of profound changes, which were implemented by the two successors of the king.

The Burmese–Siamese War (1809–1812) or the Burmese Invasion of Thalang was an armed conflict fought between Burma under Konbaung dynasty and Siam under the Chakri dynasty, during the period of June 1809 and January 1812. The war centered on the control of the Phuket Island, also known as Thalang or Junk Ceylon, and the tin rich Andaman Coast. The war also involved the Kedah Sultanate. This occasion was the last Burmese offensive expedition into Siamese territories in Thai history, with British acquisition of the Tenasserim Coast in 1826, following the First Anglo-Burmese War, removing several hundred miles of the existing land border between Siam and Burma. The war also left Phuket devastated and depopulated for many decades until its reemergence as a Tin mining center in the late 19th century.

When King Mongkut ascended the Siamese throne, he was severely threatened by the neighbouring states. The colonial powers of Britain and France had already advanced into territories which originally belonged to the Siamese sphere of influence. Mongkut and his successor Chulalongkorn (Rama V) recognised this situation and tried to strengthen the defence forces of Siam by modernisation, to absorb Western scientific and technical achievements, thus avoiding colonisation.

The two monarchs, who ruled in this epoch, were the first with Western formation. King Mongkut had lived 26 years as a wandering monk and later as an abbot of Wat Bowonniwet Vihara. He was not only skilled in the traditional culture and Buddhist sciences of Siam, but he had also dealt extensively with modern western science, drawing on the knowledge of European missionaries and his correspondence with Western leaders and the Pope. He was the first Siamese monarch to speak English.

As early as 1855, John Bowring, the British governor in Hong Kong, appeared on a warship at the mouth of the Chao Phraya River. Under the influence of Britain's achievements in neighbouring Burma, King Mongkut signed the so-called "Bowring Treaty", which abolished the royal foreign trade monopoly, abolished import duties, and granted Britain a most favourable clause. The Bowring Treaty meant the integration of Siam into the world economy, but at the same time, the royal house lost its most important sources of income. Similar treaties were concluded with all Western powers in the following years, such as in 1862 with Prussia and 1869 with Austria-Hungary. The survival diplomacy, which Siam had cultivated abroad for a long time, reached its climax in this epoch.^[59]

The integration into the global economy meant to Siam that it became a sales market for Western industrial goods and an investment for Western capital. The export of agricultural and mineral raw materials began, including the three products rice, pewter and teakwood, which were used to produce 90% of the export turnover. King Mongkut actively promoted the expansion of agricultural land by tax incentives, while the construction of traffic routes (canals, roads and later also railways) and the influx of Chinese immigrants allowed the agricultural development of new regions. Subsistence farming in the Lower Menam Valley developed into farmers actually earning money with their produce.^[60]

After the Franco-Siamese War of 1893, King Chulalongkorn realised the threat of the western colonial powers, and accelerated extensive reforms in the administration, military, economy and society of Siam, completing the development of the nation from a traditional feudalist structure based on personal domination and dependencies, whose peripheral areas were only indirectly bound to the central power (the King), to a centrally-governed national state with established borders and modern political institutions.

In 1904, 1907 and 1909, there were new border corrections in favour of France and Great Britain. When King Chulalongkorn died in 1910, Siam had achieved the borders of today's Thailand. In 1910 he was peacefully succeeded by his son Vajiravudh, who reigned as Rama VI. He had been educated at Royal Military Academy Sandhurst and University of Oxford and was an anglicised Edwardian gentleman. Indeed, one of Siam's problems was the widening gap between the Westernised royal family and upper aristocracy and the rest of the country. It took another 20 years for Western education to extend to the rest of the bureaucracy and the army.

The Franco-Siamese War of 1893, known in Thailand as Incident of R.S. 112 was a conflict between the French Third Republic and the Kingdom of Siam. Auguste Pavie, French vice consul in Luang Prabang in 1886, was the chief agent in furthering French interests in Laos. His intrigues, which took advantage of Siamese weakness in the region and periodic invasions by Vietnamese rebels from Tonkin, increased tensions between Bangkok and Paris. Following the conflict, the Siamese agreed to cede Laos to France, an act that led to the significant expansion of French Indochina. In 1896, France signed a treaty with Britain defining the border between Laos and British territory in Upper Burma. The Kingdom of Laos became a protectorate, initially placed under the Governor General of Indochina in Hanoi. Pavie, who almost single-handedly brought Laos under French rule, saw to the officialization in Hanoi.

The Anglo-Siamese Treaty of 1909 was a treaty between the United Kingdom and the Kingdom of Siam that effectively defined the modern borders between Thailand and British-controlled territories in Malaysia. Through this treaty, Siam ceded control of some territories (including the states of Kedah, Kelantan, Perlis, and Terengganu) to British control. However, it also formalized British recognition of Siamese sovereignty over the territories that remained, thus largely securing Siam's independent status. The treaty helped establish Siam as a "buffer state" between French-controlled Indochina and British-controlled Malaya. This allowed Siam to retain its independence while neighboring countries were colonized.

The successor of King Chulalongkorn was King Rama VI in October 1910, better known as Vajiravudh. He had studied law and history at the University of Oxford as the Siamese crown prince in Great Britain. After his ascension to the throne, he forgave important officials for his devoted friends, who were not part of the nobility, and even less qualified than their predecessors, an action which had hitherto been unprecedented in Siam. In his reign (1910–1925) many changes were made, which brought Siam closer to modern countries. For example, the Gregorian Calendar was introduced, all the citizens of his country had to accept Family names, women were encouraged to wear skirts and long hair fringements and a citizenship law, Principle of the "Ius sanguinis" was adopted. In 1917 the Chulalongkorn University was founded and school education was introduced for all 7 to 14-year-olds.

King Vajiravudh was a favour of literature, theatre, he translated many foreign literatures into Thai. He created the spiritual foundation for a kind of Thai nationalism, a phenomenon unknown in Siam. He was based on the unity of nation, Buddhism, and kingship, and demanded loyalty from his subjects to all these three institutions. King Vajiravudh also took refuge in an irrational and contradictory anti-Sinicism. As a result of the mass immigration, in contrast to previous immigration waves from China, women and entire families had also come into the country, which meant that the Chinese were less assimilated and retained their cultural independence. In an article published by King Vajiravudh under a pseudonym, he described the Chinese minority as Jews of the East.

In 1912, a Palace revolt, plotted by young military officers, tried unsuccessfully to overthrow and replace the king.^[61] Their goals were to change the system of government, overthrowing the ancien régime and replacing it with a modern, Westernised constitutional system, and perhaps to replace Rama VI with a prince more sympathetic to their beliefs,^[62]  but the king went against the conspirators, and sentenced many of them to long prison sentences. The members of the conspiracy consisted of military and the navy, the status of the monarchy, had become challenged.

In 1917 Siam declared war on German Empire and Austria-Hungary, mainly to gain favour with the British and the French. Siam's token participation in World War I secured it a seat at the Versailles Peace Conference, and Foreign Minister Devawongse used this opportunity to argue for the repeal of the 19th-century unequal treaties and the restoration of full Siamese sovereignty. The United States obliged in 1920, while France and Britain followed in 1925. This victory gained the king some popularity, but it was soon undercut by discontent over other issues, such as his extravagance, which became more noticeable when a sharp postwar recession hit Siam in 1919. There was also the fact that the king had no son. He obviously preferred the company of men to women (a matter which of itself did not much concern Siamese opinion, but which did undermine the stability of the monarchy due to the absence of heirs). At war's end, Siam became a founding member of the League of Nations. By 1925, the United States, the United Kingdom, and France had abandoned their extraterritorial rights in Siam.

A small circle from the rising bourgeoisie of former students (all of whom had completed their studies in Europe – mostly Paris), supported by some military men, seized power from the absolute monarchy on 24 June 1932 in an almost nonviolent revolution. The group, which called themselves Khana Ratsadon or sponsors, gathered officers, intellectuals and bureaucrats, who represented the idea of the refusal of the absolute monarchy. This military coup (Thailand's first) ended Siam's centuries-long absolute monarchy rule under the Chakri dynasty, and resulted in a bloodless transition of Siam into a constitutional monarchy, the introduction of democracy and the first constitution, and the creation of the National Assembly. Dissatisfaction caused by the economic crisis, the lack of a competent government and the rise of western-educated commoners fueled the revolution.

When Phibulsonggram succeeded Phraya Phahon as Prime Minister in September 1938, the military and civilian wings of Khana Ratsadon diverged even further, and military domination became more overt. Phibunsongkhram began moving the government towards militarism, and totalitarianism, as well as building personality cult around himself.

Negotiations with France shortly before World War II had shown that the French government was willing to make appropriate changes in the boundaries between Thailand and French Indochina, but only slightly. Following the Fall of France in 1940, Major-General Plaek Pibulsonggram (popularly known as "Phibun"), the prime minister of Thailand, decided that France's defeat gave the Thais an even better chance to regain the vassal state territories that were ceded to France during King Chulalongkorn's reign. The German military occupation of Metropolitan France rendered France's hold on its overseas possessions, including French Indochina, tenuous. The colonial administration was now cut off from outside help and outside supplies. After the Japanese invasion of French Indochina in September 1940, the French were forced to allow Japan to set up military bases. This seemingly subservient behavior lulled the Phibun regime into believing that France would not seriously resist a military confrontation with Thailand.

The defeat of France in the Battle of France was the catalyst for the Thai leadership to begin an attack on French Indochina. It suffered a heavy defeat in the sea battle of Ko Chang, but it dominated on land and in the air. The Empire of Japan, already the dominant power in the Southeast Asian region, took over the role of mediator. The negotiations ended the conflict with Thai territorial gains in the French colonies of Laos and Cambodia.

After the Franco-Thai war ended, the Thai government declared neutrality. When the Japanese invaded Thailand on 8 December 1941, a few hours after the attack on Pearl Harbor, Japan demanded the right to move troops across Thailand to the Malayan frontier. Phibun accepted Japanese demands after a brief resistance. The government improved relations with Japan by signing a military alliance in December 1941. Japanese armies used the country as a base for their invasions of Burma and Malaya.^[63] Hesitancy, however, gave way to enthusiasm after the Japanese rolled their way through Malaya in a "Bicycle Blitzkrieg" with surprisingly little resistance.^[64] The following month, Phibun declared war on Britain and the United States. South Africa and New Zealand declared war on Thailand on the same day. Australia followed soon after.^[65] All who opposed the Japanese alliance were sacked from his government. Pridi Phanomyong was appointed acting regent for the absent King Ananda Mahidol, while Direk Jayanama, the prominent foreign minister who had advocated continued resistance against the Japanese, was later sent to Tokyo as an ambassador. The United States considered Thailand to be a puppet of Japan and refused to declare war. When the allies were victorious, the United States blocked British efforts to impose a punitive peace.^[66]

The Thais and Japanese agreed that Shan State and Kayah State were to be under Thai control. On 10 May 1942, the Thai Phayap Army entered Burma's eastern Shan State, the Thai Burma Area Army entered Kayah State and some parts of central Burma. Three Thai infantry and one cavalry division, spearheaded by armoured reconnaissance groups and supported by the air force, engaged the retreating Chinese 93rd Division. Kengtung, the main objective, was captured on 27 May. Renewed offensives in June and November saw the Chinese retreat into Yunnan.^[67] The area containing the Shan States and Kayah State was annexed by Thailand in 1942. They would be ceded back to Burma in 1945.

The Seri Thai (Free Thai Movement) was an underground resistance movement against Japan founded by Seni Pramoj, the Thai ambassador in Washington. Led from within Thailand from the office of the regent Pridi, it operated freely, often with support from members of the royal family such as Prince Chula Chakrabongse, and members of the government. As Japan neared defeat and the underground anti-Japanese resistance Seri Thai steadily grew in strength, the National Assembly forced out Phibun. His six-year reign as the military commander-in-chief was at an end. His resignation was partly forced by his two grandiose plans gone awry. One was to relocate the capital from Bangkok to a remote site in the jungle near Phetchabun in north-central Thailand. The other was to build a "Buddhist city" near Saraburi. Announced at a time of severe economic difficulty, these ideas turned many government officers against him.^[68]

At war's end, Phibun was put on trial at Allied insistence on charges of having committed war crimes, mainly that of collaborating with the Axis powers. However, he was acquitted amid intense public pressure. Public opinion was still favourable to Phibun, as he was thought to have done his best to protect Thai interests, specifically using alliance with Japan to support the expansion of Thai territory in Malaya and Burma.^[69]

In December 1945, the young king Ananda Mahidol had returned to Siam from Europe, but in June 1946 he was found shot dead in his bed, under mysterious circumstances. Three palace servants were tried and executed for his murder, although there are significant doubts as to their guilt and the case remains both murky and a highly sensitive topic in Thailand today. The king was succeeded by his younger brother, Bhumibol Adulyadej. In August Pridi was forced to resign amid suspicion that he had been involved in the regicide. Without his leadership, the civilian government foundered, and in November 1947 the army, its confidence restored after the debacle of 1945, seized power.

The coup ousted the government of Pridi Banomyong front man, Luang Thamrong, who was replaced by Khuang Aphaiwong, royalist supporter, as Prime Minister of Thailand. The coup was led by military supreme leader, Phibun, and Phin Choonhavan and Kat Katsongkhram, allied with the royalists to regain their political power and Crown Property back from the reforms of the Siamese revolution of 1932. Pridi, in turn, was driven into exile, eventually settling in Beijing as a guest of the PRC. The influence of the People Party ended

Phibun's return to power coincided with the onset of the Cold War and the establishment of a communist regime in North Vietnam. There were attempted counter-coups by Pridi supporters in 1948, 1949, and 1951, the second leading to heavy fighting between the army and navy before Phibun emerged victorious. In the navy's 1951 attempt, popularly known as the Manhattan Coup, Phibun was nearly killed when the ship where he was held hostage was bombed by the pro-government air force.

Although nominally a constitutional monarchy, Thailand was ruled by a series of military governments, most prominently led by Phibun, interspersed with brief periods of democracy. Thailand took part in the Korean War. Communist Party of Thailand guerrilla forces operated inside the country from the early-1960s to 1987. They included 12,000 full-time fighters at the peak of movement, but never posed a serious threat to the state.

By 1955 Phibun was losing his leading position in the army to younger rivals led by Field Marshal Sarit Thanarat and General Thanom Kittikachorn, the Sarit's army staged a bloodless coup on 17 September 1957, ending Phibun's career for good. The coup beginning a long tradition of US-backed military regimes in Thailand. Thanom became prime minister until 1958, then yielded his place to Sarit, the real head of the regime. Sarit held power until his death in 1963, when Thanom again took the lead.

The regimes of Sarit and Thanom were strongly supported by the United States. Thailand had formally become a US ally in 1954 with the formation of the SEATO While the war in Indochina was being fought between the Vietnamese and the French, Thailand (disliking both equally) stayed aloof, but once it became a war between the US and the Vietnamese communists, Thailand committed itself strongly to the US side, concluding a secret agreement with the US in 1961, sending troops to Vietnam and Laos, and allowing the US to use airbases in the east of the country to conduct its bombing war against North Vietnam. The Vietnamese retaliated by supporting the Communist Party of Thailand's insurgency in the north, northeast, and sometimes in the south, where guerrillas co-operated with local discontented Muslims. In the postwar period, Thailand had close relations with the US, which it saw as a protector from communist revolutions in neighbouring countries. The Seventh and Thirteenth US Air Forces were headquartered at Udon Royal Thai Air Force Base.^[70]

Agent Orange, a herbicide and defoliant chemical used by the U.S. military as part of its herbicidal warfare program, Operation Ranch Hand, was tested by the United States in Thailand during the war in Southeast Asia. Buried drums were uncovered and confirmed to be Agent Orange in 1999.^[71] Workers who uncovered the drums fell ill while upgrading the airport near Hua Hin District, 100 km south of Bangkok.^[72]

The Vietnam War hastened the modernisation and Westernisation of Thai society. The American presence and the exposure to Western culture that came with it had an effect on almost every aspect of Thai life. Before the late 1960s, full access to Western culture was limited to a highly educated elite in society, but the Vietnam War brought the outside world face to face with large segments of the Thai society as never before. With US dollars pumping up the economy, the service, transportation, and construction industries grew phenomenally as did drug abuse and prostitution, which using Thailand as a "Rest and Recreation" facility by US forces.^[73] The traditional rural family unit was broken down as more and more rural Thais moved to the city to find new jobs. This led to a clash of cultures as Thais were exposed to Western ideas about fashion, music, values, and moral standards.

The population began to grow explosively as the standard of living rose, and a flood of people began to move from the villages to the cities, and above all to Bangkok. Thailand had 30 million people in 1965, while by the end of the 20th century the population had doubled. Bangkok's population had grown tenfold since 1945 and had tripled since 1970.

Educational opportunities and exposure to mass media increased during the Vietnam War years. Bright university students learned more about ideas related to Thailand's economic and political systems, resulting in a revival of student activism. The Vietnam War period also saw the growth of the Thai middle class which gradually developed its own identity and consciousness.

With the dissatisfaction of pro-US policies of Military administration that allowed the United States forces for using the country as a military bases, the high rate of prostitution problems, the freedom of press and speech were limited and influx of the corruption that lead to inequality of social classes. Student demonstrations had started in 1968 and grew in size and numbers in the early 1970s despite the continued ban on political meetings. In June 1973, nine Ramkhamhaeng University students were expelled for publishing an article in a student newspaper that was critical of the government. Shortly after, thousands of students held a protest at the Democracy Monument demanding the re-enrolment of the nine students. The government ordered the universities to shut, but shortly afterwards allowed the students to be re-enrolled.

In October another 13 students were arrested on charges of conspiracy to overthrow the government. This time the student protesters were joined by workers, businessmen, and other ordinary citizens. The demonstrations swelled to several hundred thousand and the issue broadened from the release of the arrested students to demands for a new constitution and the replacement of the current government.

On 13 October, the government released the detainees. Leaders of the demonstrations, among them Seksan Prasertkul, called off the march in accordance with the wishes of the king who was publicly against the democracy movement. In a speech to graduating students, he criticised the pro-democracy movement by telling students to concentrate on their studies and leave politics to their elders [military government]. 1973 Uprising brought about the most free era in Thai recent history, called "Age when democracy blossom" and "Democratic experiment," which ended in Thammasat University massacre and a coup on 6 October 1976.

By late 1976 moderate middle class opinion had turned away from the activism of the students, who had moved increasingly to the left. The army and the right-wing parties began a propaganda war against student liberalism by accusing student activists of being 'communists' and through formal paramilitary organizations such the Nawaphon, the Village Scouts, and the Red Gaurs, many of those students were killed. Matters came to a head in October when Thanom Kittikachorn returned to Thailand to enter a royal monastery, Wat Bovorn.

Tension between workers and factory owners became fierce, as the civil rights movement became more active after 1973. Socialism and leftist ideology gained popularity among intellectuals and the working class. The political atmosphere became even more tense. Workers were found hung in Nakhon Pathom after protesting against a factory owner. A Thai version of anti-communist McCarthyism spread widely. Whoever staged a protest could be accused of being part of a communist conspiracy.

In 1976, students protesters occupied the Thammasat University campus and held protests over the violent deaths of the workers and staged a mock hanging of the victims, one of whom allegedly bore a resemblance to Crown Prince Vajiralongkorn. Some newspapers the following day, including the Bangkok Post, published an altered version of a photo of the event, which suggested the protestors had committed lèse majesté. Rightist and ultra-conservative icons such as Samak Sundaravej blasted the protestors, instigating violent means to suppress them, culminating in the 6 October 1976 Massacre. The army unleashed the paramilitaries and mob violence followed, in which many were killed.

After the 1978 Vietnamese invasion of Cambodia and subsequent collapse of Democratic Kampuchea in 1979, the Khmer Rouge fled to the border regions of Thailand, and, with assistance from China, Pol Pot's troops managed to regroup and reorganize in forested and mountainous zones on the Thai-Cambodian border. During the 1980s and early 1990s Khmer Rouge forces operated from inside refugee camps in Thailand, in an attempt to de-stabilize the pro-Hanoi People's Republic of Kampuchea's government, which Thailand refused to recognise. Thailand and Vietnam faced off across the Thai-Cambodian border with frequent Vietnamese incursions and shellings into Thai territory throughout the 1980s in pursuit of Cambodian guerrillas who kept attacking Vietnamese occupation forces.

Much of the 1980s saw a process of democratization overseen by King Bhumibol and Prem Tinsulanonda. The two preferred constitutional rule, and acted to put an end to violent military interventions. In April 1981 a clique of junior army officers popularly known as the "Young Turks" staged a coup attempt, taking control of Bangkok. They dissolved the National Assembly and promised sweeping social changes. But their position quickly crumbled when Prem Tinsulanonda accompanied the royal family to Khorat. With King Bhumibol's support for Prem made clear, loyalist units under the palace favourite General Arthit Kamlang-ek managed to recapture the capital in an almost bloodless counterattack..

This episode raised the prestige of the monarchy still further, and also enhanced Prem's status as a relative moderate. A compromise was therefore reached. The insurgency ended and most of the ex-student guerillas returned to Bangkok under an amnesty. In December 1982, the Thai army Commander in Chief accepted flag of the Communist Party of Thailand at a widely publicized ceremony held in Banbak. Here, communist fighters and their supporters handed in their weapons and swore allegiance to the government. Prem declared the armed struggle over.^[74] The army returned to its barracks, and yet another constitution was promulgated, creating an appointed Senate to balance the popularly elected National Assembly.

Prem was also the beneficiary of the accelerating economic revolution which was sweeping south-east Asia. After the recession of the mid-1970s, economic growth took off. For the first time Thailand became a significant industrial power, and manufactured goods such as computer parts, textiles and footwear overtook rice, rubber and tin as Thailand's leading exports. With the end of the Indochina wars and the insurgency, tourism developed rapidly and became a major earner. The urban population continued to grow rapidly, but overall population growth began to decline, leading to a rise in living standards even in rural areas, although the Isaan continued to lag behind. While Thailand did not grow as fast as the "Four Asian Tigers," (namely Taiwan, South Korea, Hong Kong and Singapore) it achieved sustained growth, reaching an estimated $7100 GDP per capita (PPP) by 1990, approximately double its 1980 average.^[75]

Prem held office for eight years, surviving another coup in 1985 and two more general elections in 1983 and 1986, and remained personally popular, but the revival of democratic politics led to a demand for a more adventurous leader. In 1988 fresh elections brought former General Chatichai Choonhavan to power. Prem rejected the invitation offered by major political parties for the third term of premiership.

King Bhumibol re-appointed royalist Anand as interim prime minister until elections could be held in September 1992, which brought the Democrat Party under Chuan Leekpai to power, mainly representing the voters of Bangkok and the south. Chuan was a competent administrator who held power until 1995, when he was defeated at elections by a coalition of conservative and provincial parties led by Banharn Silpa-Archa. Tainted by corruption charges from the very beginning, Banharn's government was forced to call early elections in 1996, in which General Chavalit Yongchaiyudh's New Aspiration Party managed to gain a narrow victory.

The 1997 Constitution was the first constitution to be drafted by a popularly elected Constitutional Drafting Assembly, and was popularly called the "people's constitution".^[76] The 1997 Constitution created a bicameral legislature consisting of a 500-seat House of Representatives and a 200-seat Senate. For the first time in Thai history, both houses were directly elected.

Many human rights were explicitly acknowledged, and measures were established to increase the stability of elected governments. The House was elected by the first past the post system, where only one candidate with a simple majority could be elected in one constituency. The Senate was elected based on the provincial system, where one province could return more than one senator depending on its population size.

By allowing one faction of the military to get rich on government contracts, Chatichai provoked a rival faction, led by Generals Sunthorn Kongsompong, Suchinda Kraprayoon, and other generals of Class 5 of the Chulachomklao Royal Military Academy to stage the 1991 Thai coup d'état in February 1991, charging Chatichai's government as a corrupt regime or 'Buffet Cabinet'. The junta called itself the National Peace Keeping Council. The NPKC brought in a civilian prime minister, Anand Panyarachun, who was still responsible to the military. Anand's anti-corruption and straightforward measures proved popular. Another general election was held in March 1992.

The winning coalition appointed coup leader Suchinda Kraprayoon to become Prime Minister, in effect breaking a promise he had made earlier to King Bhumibol and confirming the widespread suspicion that the new government was going to be a military regime in disguise. However, the Thailand of 1992 was not the Siam of 1932. Suchinda's action brought hundreds of thousands of people out in the largest demonstrations ever seen in Bangkok, led by the former governor of Bangkok, Major-General Chamlong Srimuang.

Suchinda brought military units personally loyal to him into the city and tried to suppress the demonstrations by force, leading to a massacre and riots in the heart of the capital, Bangkok, in which hundreds died. Rumours spread out as there was a rift in the armed forces. Amidst the fear of civil war, King Bhumibol intervened: he summoned Suchinda and Chamlong to a televised audience, and urged them to follow the peaceful solution. This meeting resulted in Suchinda's resignation.

Soon after coming into office, Prime Minister Chavalit was confronted by the Asian Financial Crisis in 1997. After coming under strong criticism for his handling of the crisis, Chavilit resigned in November 1997 and Chuan returned to power. Chuan came to an agreement with the International Monetary Fund which stabilised the currency and allowed IMF intervention on the Thai economic recovery. In contrast to the country's previous history, the crisis was resolved by civilian rulers under democratic procedures.

During the 2001 election Chuan's agreement with the IMF and use of injection funds to boost the economy were a cause for great debate, whilst Thaksin's policies appealed to the mass electorate. Thaksin campaigned effectively against the old politics, corruption, organized crime, and drugs. In January 2001 he had a sweeping victory at the polls, winning a larger popular mandate (40%) than any Thai prime minister has ever had in a freely elected National Assembly.

Thaksin's Thai Rak Thai Party came to power through a general election in 2001, where it won a near-majority in the House of Representatives. As prime minister, Thaksin launched a platform of policies, popularly dubbed "Thaksinomics", which focused on promoting domestic consumption and providing capital especially to the rural populace. By delivering on electoral promises, including populist policies such as the One Tambon One Product project and the 30-baht universal healthcare scheme, his government enjoyed high approval, especially as the economy recovered from the effects of the 1997 Asian financial crisis. Thaksin became the first democratically elected prime minister to complete a four-year term in office, and Thai Rak Thai won a landslide victory in the 2005 general election.^[77]

However, Thaksin's rule was also marked by controversy. He had adopted an authoritarian "CEO-style" approach in governing, centralising power and increasing intervention in the bureaucracy's operations. While the 1997 constitution had provided for greater government stability, Thaksin also used his influence to neutralise the independent bodies designed to serve as checks and balances against the government. He threatened critics and manipulated the media into carrying only positive commentary. Human rights in general deteriorated, with a "war on drugs" resulting in over 2,000 extrajudicial killings. Thaksin responded to the South Thailand insurgency with a highly confrontational approach, resulting in marked increases in violence.^[78]

Public opposition to Thaksin's government gained much momentum in January 2006, sparked by the sale of Thaksin's family's holdings in Shin Corporation to Temasek Holdings. A group known as the People's Alliance for Democracy (PAD), led by media tycoon Sondhi Limthongkul, began holding regular mass rallies, accusing Thaksin of corruption. As the country slid into a state of political crisis, Thaksin dissolved the House of Representatives, and a general election was held in April. However, opposition parties, led by the Democrat Party, boycotted the election. The PAD continued its protests, and although Thai Rak Thai won the election, the results were nullified by the Constitutional Court due to a change in arrangement of voting booths. A new election was scheduled for October, and Thaksin continued to serve as head of the caretaker government as the country celebrated King Bhumibol's diamond jubilee on 9 June 2006.^[79]

On 19 September 2006, the Royal Thai Army under General Sonthi Boonyaratglin staged a bloodless coup d'état and overthrew the caretaker government. The coup was widely welcomed by the anti-Thaksin protesters, and the PAD dissolved itself. The coup leaders established a military junta called the Council for Democratic Reform, later known as the Council for National Security. It annulled the 1997 constitution, promulgated an interim constitution and appointed an interim government with former army commander General Surayud Chulanont as prime minister. It also appointed a National Legislative Assembly to serve the functions of parliament and a Constitution Drafting Assembly to create a new constitution. The new constitution was promulgated in August 2007 following a referendum.^[80]

As the new constitution came into effect, a general election was held in December 2007. Thai Rak Thai and two coalition parties had earlier been dissolved as a result of a ruling in May by the junta-appointed Constitutional Tribunal, which found them guilty of election fraud, and their party executives were barred from politics for five years. Thai Rak Thai's former members regrouped and contested the election as the People's Power Party (PPP), with veteran politician Samak Sundaravej as party leader. The PPP courted the votes of Thaksin's supporters, won the election with a near-majority, and formed government with Samak as prime minister.^[80]

Samak's government actively sought to amend the 2007 Constitution, and as a result the PAD regrouped in May 2008 to stage further anti-government demonstrations. The PAD accused the government of trying to grant amnesty to Thaksin, who was facing corruption charges. It also raised issues with the government's support of Cambodia's submission of Preah Vihear Temple for World Heritage Site status. This led to an inflammation of the border dispute with Cambodia, which later resulted in multiple casualties. In August, the PAD escalated its protest and invaded and occupied the Government House, forcing government officials to relocate to temporary offices and returning the country to a state of political crisis. Meanwhile, the Constitutional Court found Samak guilty of conflict of interest due to his working for a cooking TV programme, terminating his premiership in September. Parliament then chose PPP deputy leader Somchai Wongsawat to be the new prime minister. Somchai is a brother-in-law of Thaksin's, and the PAD rejected his selection and continued its protests.^[81]

Living in exile since the coup, Thaksin returned to Thailand only in February 2008 after the PPP had come to power. In August, however, amid the PAD protests and his and his wife's court trials, Thaksin and his wife Potjaman jumped bail and applied for asylum in the United Kingdom, which was denied. He was later found guilty of abuse of power in helping Potjaman buy land on Ratchadaphisek Road, and in October was sentenced in absentia by the Supreme Court to two years in prison.^[82]

The PAD further escalated its protest in November, forcing the closure of both of Bangkok's international airports. Shortly after, on 2 December, the Constitutional Court dissolved the PPP and two other coalition parties for electoral fraud, ending Somchai's premiership.^[83] The opposition Democrat Party then formed a new coalition government, with Abhisit Vejjajiva as prime minister.^[84]

On 22 May 2014, the Royal Thai Armed Forces, led by General Prayut Chan-o-cha, Commander of the Royal Thai Army (RTA), launched a coup d'état, the 12th since the country's first coup in 1932, against the caretaker government of Thailand, following six months of political crisis.^[85] The military established a junta called the National Council for Peace and Order (NCPO) to govern the nation. The coup ended the political conflict between the military-led regime and democratic power, which had been present since the 2006 Thai coup d'état known as the 'unfinished coup'.^[86] 7 years later, it had developed into the 2020 Thai protests to reform the monarchy of Thailand.

After dissolving the government and the Senate, the NCPO vested executive and legislative powers in its leader and ordered the judicial branch to operate under its directives. In addition, it partially repealed the 2007 constitution, save the second chapter which concerns the king,^[87] declared martial law and curfew nationwide, banned political gatherings, arrested and detained politicians and anti-coup activists, imposed Internet censorship and took control of the media.

The NCPO issued an interim constitution granting itself amnesty and sweeping power.^[88] The NCPO also established a military-dominated national legislature which later unanimously elected General Prayut as the new prime minister of the country.^[89]

King Bhumibol Adulyadej of Thailand died at the age of 88 on 13 October 2016, after a long illness. A year-long period of mourning was subsequently announced. A royal cremation ceremony took place over five days at the end of October 2017. The actual cremation, which was not broadcast on television, was held in the late evening of 26 October 2017. Following cremation his remains and ashes were taken to the Grand Palace and were enshrined at the Chakri Maha Phasat Throne Hall (royal remains), the Royal Cemetery at Wat Ratchabophit and the Wat Bowonniwet Vihara Royal Temple (royal ashes). Following burial, the mourning period officially ended on midnight of 30 October 2017 and Thais resumed wearing colors other than black in public.