Parthian Empire

In 245 BCE, Andragoras, the Seleucid governor (satrap) of Parthia proclaimed independence from the Seleucids, when - following the death of Antiochus II - Ptolemy III seized control of the Seleucid capital at Antioch, and "so left the future of the Seleucid dynasty for a moment in question. "Meanwhile, "a man called Arsaces, of Scythian or Bactrian origin, [was] elected leader of the Parni tribes." Following the secession of Parthia from the Seleucid Empire and the resultant loss of Seleucid military support, Andragoras had difficulty in maintaining his borders, and about 238 BCE—under the command of "Arsaces and his brother Tiridates"—the Parni invaded Parthia and seized control of Astabene (Astawa), the northern region of that territory, the administrative capital of which was Kabuchan (Kuchan in the vulgate). A short while later the Parni seized the rest of Parthia from Andragoras, killing him in the process. With the conquest of the province, the Arsacids became known as Parthians in Greek and Roman sources. Arsaces I became the first king of Parthia as well as the founder and eponym of the Arsacid dynasty of Parthia.

Antiochus III launched a campaign to regain control of the eastern provinces, and after defeating the Parthians in battle, he successfully regained control over the region. The Parthians were forced to accept vassal status and now only controlled the land conforming to the former Seleucid province of Parthia. However, Parthia's vassalage was only nominal at best and only because the Seleucid army was on their doorstep. For his retaking of the eastern provinces and establishing the Seleucid borders as far east as they had been under Seleucus I Nicator, Antiochus was awarded the title great by his nobles. Luckily for the Parthians, the Seleucid Empire had many enemies, and it was not long before Antiochus led his forces west to fight Ptolemaic Egypt and the rising Roman Republic.

The Seleucids were unable to further intervene in Parthian affairs following the Seleucid defeat at Magnesia in 190 BCE. Priapatius (r. c. 191–176 BCE) succeeded Arsaces II, and Phraates I (r. c. 176–171 BCE) eventually ascended the Parthian throne. Phraates I ruled Parthia without further Seleucid interference.

While the Parthians regained the territories lost in the west, another threat arose in the east. In 177–176 BCE the nomadic confederation of the Xiongnu dislodged the nomadic Yuezhi from their homelands in what is now Gansu province in Northwest China; the Yuezhi then migrated west into Bactria and displaced the Saka (Scythian) tribes. The Saka were forced to move further west, where they invaded the Parthian Empire's northeastern borders. Mithridates was thus forced to retire to Hyrcania after his conquest of Mesopotamia.

Some of the Saka were enlisted in Phraates' forces against Antiochus. However, they arrived too late to engage in the conflict. When Phraates refused to pay their wages, the Saka revolted, which he tried to put down with the aid of former Seleucid soldiers, yet they too abandoned Phraates and joined sides with the Saka. Phraates II marched against this combined force, but he was killed in battle. The Roman historian Justin reports that his successor Artabanus I (r. c. 128–124 BCE) shared a similar fate fighting nomads in the east.

Phraates I is recorded as expanding Parthia's control past the Gates of Alexander and occupied Apamea Ragiana. The locations of these are unknown. Yet the greatest expansion of Parthian power and territory took place during the reign of his brother and successor Mithridates I (r. c. 171–132 BCE), whom Katouzian compares to Cyrus the Great (d. 530 BCE), founder of the Achaemenid Empire.

Mithridates I turned his sights on the Greco-Bactrian Kingdom which had been considerably weakened as a result of its wars against the neighbouring Sogdians, Drangianans and Indians. The new Greco-Bactrian king Eucratides I (r. 171–145 BCE) had usurped the throne and was as a result met with opposition, such as the rebellion by the Arians, which was possibly supported by Mithridates I, as it would serve to his advantage. Sometime between 163–155 BCE, Mithridates I invaded the domains of Eucratides, whom he defeated and seized Aria, Margiana and western Bactria from. Eucratides was supposedly made a Parthian vassal, as is indicated by the classical historians Justin and Strabo. Merv became a stronghold of Parthian dominance in the northeast. Some of Mithridates I's bronze coins portray an elephant on the reverse with the legend "of the Great King, Arsaces." The Greco-Bactrians minted coins with images of elephants, which suggests that Mithridates I's coin mints of the very animal was possibly to celebrate his conquest of Bactria.

Turning his sights on the Seleucid realm, Mithridates I invaded Media and occupied Ecbatana in 148 or 147 BCE; the region had recently become unstable after the Seleucids suppressed a rebellion led by Timarchus. Mithridates I afterwards appointed his brother Bagasis as the governor of the area. This victory was followed by the Parthian conquest of Media Atropatene. In 141 BCE, Mithridates I captured Babylonia in Mesopotamia, where he had coins minted at Seleucia and held an official investiture ceremony. There Mithridates I appears to have introduced a parade of the New Year festival in Babylon, by which a statue of the ancient Mesopotamian god Marduk was led along parade way from the Esagila temple by holding the hands of the goddess Ishtar. With Mesopotamia now in Parthian hands, the administrative focus of the empire relocated towards there instead of eastern Iran. Mithridates I shortly afterwards retired to Hyrcania, whilst his forces subdued the kingdoms of Elymais and Characene and occupied Susa. By this time, Parthian authority extended as far east as the Indus River.

The Seleucid ruler Demetrius II Nicator was at first successful in his efforts to reconquer Babylonia, however, the Seleucids were eventually defeated and Demetrius himself was captured by Parthian forces in 138 BCE. He was afterwards paraded in front of the Greeks of Media and Mesopotamia with the intention of making them to accept Parthian rule. Afterwards, Mithridates I had Demetrius sent to one of his palaces in Hyrcania. There Mithridates I treated his captive with great hospitality; he even married his daughter Rhodogune to Demetrius. According to Justin, Mithridates I had plans for Syria, and planned to use Demetrius as his instrument against the new Seleucid ruler Antiochus VII Sidetes (r. 138–129 BCE). His marriage to Rhodogune was in reality an attempt by Mithridates I to incorporate the Seleucid lands into the expanding Parthian realm. Mithridates I then punished the Parthian vassal kingdom of Elymais for aiding the Seleucids–he invaded the region once more and captured two of their major cities.

Around the same period, Mithridates I conquered the southwestern Iranian region of Persis and installed Wadfradad II as its frataraka; he granted him more autonomy, most likely in an effort to maintain healthy relations with Persis as the Parthian Empire was under constant conflict with the Saka, Seleucids, and the Mesenians. He was seemingly the first Parthian monarch to have an influence on the affairs of Persis. The coinage of Wadfradad II shows influence from the coins minted under Mithridates I. Mithridates I died in c. 132 BCE, and was succeeded by his son Phraates II.

Antiochus VII Sidetes, a brother of Demetrius, assumed the Seleucid throne and married the latter's wife Cleopatra Thea. After defeating Diodotus Tryphon, Antiochus initiated a campaign in 130 BCE to retake Mesopotamia, now under the rule of Phraates II (r. c. 132–127 BCE). The Parthian general Indates was defeated along the Great Zab, followed by a local uprising where the Parthian governor of Babylonia was killed. Antiochus conquered Babylonia and occupied Susa, where he minted coins. After advancing his army into Media, the Parthians pushed for peace, which Antiochus refused to accept unless the Arsacids relinquished all lands to him except Parthia proper, paid heavy tribute, and released Demetrius from captivity. Arsaces released Demetrius and sent him to Syria, but refused the other demands. By spring 129 BCE, the Medes were in open revolt against Antiochus, whose army had exhausted the resources of the countryside during winter. While attempting to put down the revolts, the main Parthian force swept into the region and killed Antiochus at the Battle of Ecbatana in 129 BCE. His body was sent back to Syria in a silver coffin; his son Seleucus was made a Parthian hostage and a daughter joined Phraates' harem.

According to Justin, Mithridates II avenged the death of his "parents or ancestors" (ultor iniuriae parentum), which indicates that he fought and defeated the Tocharians, who had killed Artabanus I and Phraates II. Mithridates II also reconquered western Bactria from the Scythians. Parthian coinage and scattered reports imply that Mithridates II ruled Bactra, Kampyrtepa, and Termez, which means that he had reconquered the very lands that been conquered by his namesake Mithridates I (r. 171 – 132 BCE). Control over the middle Amu Darya including Amul was vital for the Parthians, in order to thwart incursions by nomads from Transoxiana, particularly from Sogdia. Parthian coins continued to be minted in western Bactria and in the middle Amu Darya until the reign of Gotarzes II (r. 40–51 CE).

Nomadic invasions had also reached the eastern Parthian province of Drangiana, where strong Saka dominions had been established, thus giving the rise to the name Sakastan ("land of the Saka"). These nomads had probably migrated to the area due to the pressure that Artabanus I and Mithridates II had been putting against them in the north. Sometime between 124 and 115 BCE, Mithridates II sent an army led by a general of the House of Suren to recapture to the region. After Sakastan was incorporated back into the Parthian realm, Mithridates II rewarded the region to the Surenid general as his fiefdom. The eastern extent of the Parthian Empire under Mithridates II reached as far as Arachosia.

Following the diplomatic venture of Zhang Qian into Central Asia during the reign of Emperor Wu of Han (r. 141–87 BCE), the Han Empire of China sent a delegation to Mithridates II's court in 121 BCE. The Han embassy opened official trade relations with Parthia via the Silk Road yet did not achieve a desired military alliance against the confederation of the Xiongnu. The Parthian Empire was enriched by taxing the Eurasian caravan trade in silk, the most highly priced luxury good imported by the Romans. Pearls were also a highly valued import from China, while the Chinese purchased Parthian spices, perfumes, and fruits. Exotic animals were also given as gifts from the Arsacid to Han courts; in 87 CE Pacorus II of Parthia sent lions and Persian gazelles to Emperor Zhang of Han (r. 75–88 CE). Besides silk, Parthian goods purchased by Roman merchants included iron from India, spices, and fine leather. Caravans traveling through the Parthian Empire brought West Asian and sometimes Roman luxury glasswares to China. The merchants of Sogdia, speaking an Eastern Iranian language, served as the primary middlemen of this vital silk trade between Parthia and Han China.

Ctesiphon was founded in the late 120s BCE. It was built on the site of a military camp established across from Seleucia by Mithridates I of Parthia. The reign of Gotarzes I saw Ctesiphon reach a peak as a political and commercial center. The city became the Empire's capital circa 58 BCE during the reign of Orodes II. Gradually, the city merged with the old Hellenistic capital of Seleucia and other nearby settlements to form a cosmopolitan metropolis.

In approximately 120 BCE, the Parthian king Mithridates II (r. 124–91 BCE) invaded Armenia and made its king Artavasdes I acknowledge Parthian suzerainty. Artavasdes I was forced to give the Parthians Tigranes, who was either his son or nephew, as a hostage. Tigranes lived in the Parthian court at Ctesiphon, where he was schooled in Parthian culture. Tigranes remained a hostage at the Parthian court until c. 96/95 BCE, when Mithridates II released him and appointed him as the king of Armenia. Tigranes ceded an area called "seventy valleys" in the Caspiane to Mithridates II, either as a pledge or because Mithridates II demanded it. Tigranes' daughter Ariazate had also married a son of Mithridates II, which has been suggested by the modern historian Edward Dąbrowa to have taken place shortly before he ascended the Armenian throne as a guarantee of his loyalty. Tigranes would remain a Parthian vassal until the end of the 80's BCE.

The following year, Mithridates II attacked Adiabene, Gordyene and Osrhoene and conquered these city states, shifting the western border of the Parthian realm to the Euphrates. There the Parthians encountered the Romans for the first time.

In 96 BCE Mithridates II sent one of his officials, Orobazus, as an envoy to Sulla. As the Romans were increasing in power and influence, the Parthians sought friendly relations with the Romans and thus wanted to reach an agreement that assured mutual respect between the two powers. Negotiations followed in which Sulla apparently gained the upper hand, which made Orobazus and the Parthians look like supplicants. Orobazus would later be executed.

The so-called "Parthian Dark Age" refers to a period of three decades in the history of Parthian Empire between the death (or last years) of Mithridates II in 91 BCE, and the accession to the throne of Orodes II in 57 BCE, with various date ranges being mentioned by scholars. It is called a "Dark Age" due to a lack of clear information on the events of this period in the empire, except a series of, apparently overlapping, reigns.

No written source describing this period has survived, and scholars have been unable to clearly reconstruct the succession of rulers and their regnal years using the existing numismatic sources due to their ambiguities. No legal or administrative document from this period has been preserved. Multiple theories have been proposed to partially address this numismatic problem.

Based on the classical sources, the names of the rulers in this period are Sinatruces and his son Phraates (III), Mithridates (III/IV), Orodes (II), the sons of Phraates III, and a certain Darius (I), ruler of Media (or Media Atropatene?). Two other names, Gotarzes (I) and Orodes (I) are attested in dated cuneiform tablets from Babylon.

Following the outbreak of the Third Mithridatic War, Mithridates VI of Pontus (r. 119–63 BCE), an ally of Tigranes II of Armenia, requested aid from Parthia against Rome, but Sinatruces refused help. When the Roman commander Lucullus marched against the Armenian capital Tigranocerta in 69 BCE, Mithridates VI and Tigranes II requested the aid of Phraates III (r. c. 71–58). Phraates did not send aid to either, and after the fall of Tigranocerta he reaffirmed with Lucullus the Euphrates as the boundary between Parthia and Rome.

Marcus Licinius Crassus, one of the triumvirs, who was now proconsul of Syria, invaded Parthia in 53 BCE in belated support of Mithridates. As his army marched to Carrhae (modern Harran, southeastern Turkey), Orodes II invaded Armenia, cutting off support from Rome's ally Artavasdes II of Armenia (r. 53–34 BCE). Orodes persuaded Artavasdes to a marriage alliance between the crown prince Pacorus I of Parthia (d. 38 BCE) and Artavasdes' sister.

Surena, with an army entirely on horseback, rode to meet Crassus. Surena's 1,000 cataphracts (armed with lances) and 9,000 horse archers were outnumbered roughly four to one by Crassus' army, comprising seven Roman legions and auxiliaries including mounted Gauls and light infantry. Using a baggage train of about 1,000 camels, the Parthian army provided the horse archers with a constant supply of arrows. The horse archers employed the "Parthian shot" tactic: feigning retreat to draw enemy out, then turning and shooting at them when exposed. This tactic, executed with heavy composite bows on the flat plain, devastated Crassus' infantry.

With some 20,000 Romans dead, approximately 10,000 captured, and roughly another 10,000 escaping west, Crassus fled into the Armenian countryside. At the head of his army, Surena approached Crassus, offering a parley, which Crassus accepted. However, he was killed when one of his junior officers, suspecting a trap, attempted to stop him from riding into Surena's camp. Crassus' defeat at Carrhae was one of the worst military defeats of Roman history. Parthia's victory cemented its reputation as a formidable if not equal power with Rome. With his camp followers, war captives, and precious Roman booty, Surena traveled some 700 km (430 mi) back to Seleucia where his victory was celebrated. However, fearing his ambitions even for the Arsacid throne, Orodes had Surena executed shortly thereafter.

Parthian forces made a number of raids into Roman territory after the defeat of the Roman army under Crassus at the Battle of Carrhae. The Romans under Gaius Cassius Longinus defended the border against these Parthian incursions successfully. However, in 40 BCE a Parthian invasion force allied with rebel Roman forces who served under Quintus Labienus attacked the eastern Roman provinces, they enjoyed great success as Labienus took all of Asia Minor except for a few cities, while the young prince Pacorus I of Parthia took over Syria and the Hasmonean state in Judea. After these incidents Mark Antony gave command of the eastern Roman forces to his lieutenant, Publius Ventidius Bassus, a skilled military general who served under Julius Caesar. Ventidius landed unexpectedly on the coast of Asia Minor, which forced Labienus to fall back to Cilicia where he received additional Parthian reinforcements from Pacorus. After Labienus had regrouped with Pacorus’s additional forces, his and Ventidius’s armies met somewhere at the Taurus Mountains.

The Battle of the Cilician Gates in 39 BCE was a decisive victory for the Roman general Publius Ventidius Bassus over the Parthian army and its Roman allies who served under Quintus Labienus in Asia Minor.

Antony's Parthian War was a military campaign by Mark Antony, the eastern triumvir of the Roman Republic, against the Parthian Empire under Phraates IV.

Julius Caesar had planned an invasion of Parthia but was assassinated before he could implement it. In 40 BCE, the Parthians were joined by Pompeian forces and briefly captured much of the Roman East, but a force sent by Antony defeated them and reversed their gains.

Allying with several kingdoms, including Armenia, Antony began a campaign against Parthia with a massive force in 36 BCE. The Euphrates front was found to be strong and so Antony chose the route via Armenia. Upon entering Atropatene, the Roman baggage train and siege engines, which had taken a different route, were destroyed by a Parthian cavalry force. Antony still besieged the Atropatene capital but was unsuccessful.

The arduous journey of retreat to Armenia and then Syria further inflicted heavy losses on his force. Roman sources blame the Armenian king for the heavy defeat, but modern sources note Antony's poor management and planning. Antony later invaded and pillaged Armenia and executed its king.

The Indo-Parthian Kingdom was a Parthian kingdom founded by Gondophares, and active from 19 CE to c. 226 CE. At their zenith, they ruled an area covering parts of eastern Iran, various parts of Afghanistan and the northwest regions of the Indian subcontinent (most of modern Pakistan and parts of northwestern India). The rulers may have been members of the House of Suren, and the kingdom has even been called the "Suren Kingdom" by some authors.The kingdom was founded in 19 when the governor of Drangiana (Sakastan) Gondophares declared independence from the Parthian Empire. He would later make expeditions to the east, conquering territory from the Indo-Scythians and Indo-Greeks, thus transforming his kingdom into an empire. The domains of the Indo-Parthians were greatly reduced following the invasions of the Kushans in the second half of the 1st. century. They managed to retain control of Sakastan, until its conquest by the Sasanian Empire in c. 224/5. In Baluchistan, the Paratarajas, a local Indo-Parthian dynasty, fell into the orbit of the Sasanian Empire circa 262 CE.

The Roman–Parthian War of 58–63 or the War of the Armenian Succession was fought between the Roman Empire and the Parthian Empire over control of Armenia, a vital buffer state between the two realms. Armenia had been a Roman client state since the days of Emperor Augustus, but in 52/53, the Parthians succeeded in installing their own candidate, Tiridates, on the Armenian throne.

These events coincided with the accession of Nero to the imperial throne in Rome, and the young emperor decided to react vigorously. The war, which was the only major foreign campaign of his reign, began with rapid success for the Roman forces, led by the able general Gnaeus Domitius Corbulo. They overcame the forces loyal to Tiridates, installed their own candidate, Tigranes VI, on the Armenian throne, and left the country. The Romans were aided by the fact that the Parthian king Vologases was embroiled in the suppression of a series of revolts in his own country. As soon as these had been dealt with, however, the Parthians turned their attention to Armenia, and after a couple of years of inconclusive campaigning, inflicted a heavy defeat on the Romans in the Battle of Rhandeia.

The conflict ended soon after, in an effective stalemate and a formal compromise: a Parthian prince of the Arsacid line would henceforth sit on the Armenian throne, but his nomination had to be approved by the Roman emperor. This conflict was the first direct confrontation between Parthia and the Romans since Crassus' disastrous expedition and Mark Antony's campaigns a century earlier, and would be the first of a long series of wars between Rome and Iranian powers over Armenia.

The Alani are also mentioned in the context of a nomadic invasion of the Parthian Empire in 72 CE. They swept through Parthian territory from the northeast and reached Media in present-day western Iran, capturing the royal harem of the ruling Arsacid monarch, Vologeses I (Valakhsh I). From Media, they attacked Armenia and defeated the armies of Tiridates, who was nearly captured. The Parthians and Armenians were so alarmed by the devastation wrought by these nomadic invaders that they appealed to Rome for urgent assistance, but the Romans declined to help (Frye: 240). Fortunately for the Parthians and Armenians, the Alani returned to the vast steppes of Eurasia after they had collected a large quantity of booty (Colledge: 52).

In 97 CE, the Han Chinese general Ban Chao, the Protector-General of the Western Regions, sent his emissary Gan Ying on a diplomatic mission to reach the Roman Empire. Gan visited the court of Pacorus II at Hecatompylos before departing towards Rome. He traveled as far west as the Persian Gulf, where Parthian authorities convinced him that an arduous sea voyage around the Arabian Peninsula was the only means to reach Rome. Discouraged by this, Gan Ying returned to the Han court and provided Emperor He of Han (r. 88–105 CE) with a detailed report on the Roman Empire based on oral accounts of his Parthian hosts. William Watson speculates that the Parthians would have been relieved at the failed efforts by the Han Empire to open diplomatic relations with Rome, especially after Ban Chao's military victories against the Xiongnu in eastern Central Asia.

Trajan's Parthian campaign was engaged by Roman Emperor Trajan in 115 against the Parthian Empire in Mesopotamia. The war was initially successful for the Romans, but a series of setbacks, including wide-scale rebellions in the Eastern Mediterranean and North Africa and Trajan's death in 117, ended in a Roman withdrawal.

In 113, Trajan decided that the moment was ripe for a final resolution of the "eastern question" by the decisive defeat of Parthia and the annexation of Armenia. His conquests marked a deliberate change of Roman policy towards Parthia and a shift of emphasis in the empire's "grand strategy". In 114, Trajan invaded Armenia; annexed it as a Roman province and killed Parthamasiris, who had been placed on the Armenian throne by his relative, Parthia King Osroes I.

In 115, the Roman emperor overran northern Mesopotamia and annexed it to Rome as well. Its conquest was deemed necessary since otherwise, the Armenian salient could be cut off by the Parthians from the south. The Romans then captured the Parthian capital, Ctesiphon, before they sailed downriver to the Persian Gulf.

However, revolts erupted that year in the Eastern Mediterranean, North Africa and northern Mesopotamia, while a major Jewish revolt broke out in Roman territory, which severely stretched Roman military resources. Trajan failed to take Hatra, which avoided a total Parthian defeat. Parthian forces attacked key Roman positions, and Roman garrisons at Seleucia, Nisibis and Edessa were evicted by the local populaces. Trajan subdued the rebels in Mesopotamia; installed a Parthian prince, Parthamaspates, as a client ruler and withdrew to Syria. Trajan died in 117 before he could renew the war

The Roman–Parthian War of 161–166 (also called the Parthian War of Lucius Verus) was fought between the Roman and Parthian Empires over Armenia and Upper Mesopotamia. It concluded in 166 after the Romans made successful campaigns into Lower Mesopotamia and Media and sacked Ctesiphon, the Parthian capital.

In early 197 Severus left Rome and sailed to the east. He embarked at Brundisium and probably landed at the port of Aegeae in Cilicia, travelling on to Syria by land. He immediately gathered his army and crossed the Euphrates. Abgar IX, titular King of Osroene but essentially only the ruler of Edessa since the annexation of his kingdom as a Roman province, handed over his children as hostages and assisted Severus' expedition by providing archers. King Khosrov I of Armenia also sent hostages, money and gifts.

Severus travelled on to Nisibis, which his general Julius Laetus had prevented from falling into Parthian hands. Afterwards Severus returned to Syria to plan a more ambitious campaign. The following year he led another, more successful campaign against the Parthian Empire, reportedly in retaliation for the support it had given to Pescennius Niger. His legions sacked the Parthian royal city of Ctesiphon and he annexed the northern half of Mesopotamia to the empire; Severus took the title Parthicus Maximus, following the example of Trajan. However, he was unable to capture the fortress of Hatra, even after two lengthy sieges—just like Trajan, who had tried nearly a century before. During his time in the east, though, Severus also expanded the Limes Arabicus, building new fortifications in the Arabian Desert from Basie to Dumatha. These wars led to the Roman acquisition of northern Mesopotamia, as far as the areas around Nisibis and Singara.

The Parthian war of Caracalla was an unsuccessful campaign by the Roman Empire under Caracalla against the Parthian Empire in 216–17 CE. It was the climax of a four-year period, starting in 213, when Caracalla pursued a lengthy campaign in central and eastern Europe and the Near East. After intervening to overthrow rulers in client kingdoms adjoining Parthia, he invaded in 216 using an abortive wedding proposal to the Parthian king Artabanus's daughter as a casus belli. His forces carried out a campaign of massacres in the northern regions of the Parthian Empire before withdrawing to Asia Minor, where he was assassinated in April 217. The war was ended the following year after Parthian victory at a battle at Nisibis, with the Romans paying a huge sum of war reparations to the Parthians.

The Battle of Nisibis was fought in the summer of 217 between the armies of the Roman Empire under the newly ascended emperor Macrinus and the Parthian army of King Artabanus IV. It lasted for three days, and ended with a bloody Parthian victory, with both sides suffering large casualties. As a result of the battle, Macrinus was forced to seek peace, paying the Parthians a huge sum and abandoning the invasion of Mesopotamia that Caracalla had begun a year before.

In June 218, Macrinus was defeated by the forces supporting Elagabalus outside Antioch, while Artabanus faced the uprising of the Persian Sassanid clan under Ardashir I. Nisibis was thus the last major battle between Rome and Parthia, as the Parthian dynasty was overthrown by Ardashir few years later. However, warfare between Rome and Persia soon resumed, as Ardashir and Macrinus' successor Alexander Severus fought over Mesopotamia, and hostilities continued intermittently until the Muslim conquests.

The Parthian Empire, weakened by internal strife and wars with Rome, was soon to be followed by the Sasanian Empire. Indeed, shortly afterward, Ardashir I, the local Iranian ruler of Persis (modern Fars Province, Iran) from Istakhr began subjugating the surrounding territories in defiance of Arsacid rule. He confronted Artabanus IV at the Battle of Hormozdgān on 28 April 224 CE, perhaps at a site near Isfahan, defeating him and establishing the Sasanian Empire. There is evidence, however, that suggests Vologases VI continued to mint coins at Seleucia as late as 228 CE.

The Sassanians would not only assume Parthia's legacy as Rome's Persian nemesis, but they would also attempt to restore the boundaries of the Achaemenid Empire by briefly conquering the Levant, Anatolia, and Egypt from the Eastern Roman Empire during the reign of Khosrau II (r. 590–628 CE). However, they would lose these territories to Heraclius—the last Roman emperor before the Arab conquests. Nevertheless, for a period of more than 400 years, they succeeded the Parthian realm as Rome's principal rival.