Ardashir I and Rome ｜ The First Clash Between Persia and the Roman Empire

Across nearly five centuries, the Parthian Empire passed through distinct phases of expansion, consolidation, and eventual decline. Its long history can be understood through four major periods. The first period, spanning 247 to 165 BC, marks the era in which the Parthians were still a small kingdom in the northeastern regions of Iran. The second period, from 165 to 70 BC, saw the Parthians, under the leadership of Mithridates I and Mithridates II, rise to become a dominant imperial power across Western Asia. The third period begins in 70 BC and extends to 50 AD, although the Parthians achieved remarkable victories against the Romans in the early years of this era. A long and destructive internal conflict soon followed. The seemingly endless civil war that erupted after the death of Phrates IV gradually eroded the military strength of the Arsacid House. The fourth and final period recounts the decline and fall of the Parthian Empire. Although this era began under the rule of one of the dynasty's greatest kings, it soon brought little but misfortune. When Volagas I ascended the throne, the Kushan Empire had begun its first major wave of territorial expansion from the east. In the west, the Roman Empire, after 50 years of peace, declared war on the Parthians. All of this occurred while Volagas himself was forced to suppress rivals to his own crown. Volagas' first decisive act was the elimination of Vardanes, who had been minting in Seleucia. He then marched into Armenia, installing his brother Tiridates on the throne. This move, perhaps his greatest achievement, secured Parthian rule in Armenia, where a branch of the Arsacid family continued to reign even after the collapse of the Parthian Empire in Iran, surviving well into the 5th century AD. The conquest of Armenia marked the beginning of a new conflict with the Roman Empire. At the same time, the Kushans launched their own attacks against the eastern frontiers of the Parthian realm. Volagas I first dealt with the Kushans, defeating them, and then expelled the Romans from Armenia. The peace agreement that followed between Rome and Parthia endured for nearly half a century. Volagas was not only a gifted military commander, he also paid exceptional attention to Persian tradition and culture. On his coinage, the Parthian language appears alongside Greek, and he ordered the scattered texts of the Avesta, the sacred scripture of the Zoroastrians, to be collected once more. He also founded several new cities bearing his own name. Although Volagas has succeeded in restoring Parthian strength, the civil war that erupted immediately after his death ushered in another dark era in Arsacid history. During this period, the Romans, under the leadership of Trajan, crossed the Euphrates and, for the first time, captured Ctesiphon. Although the Parthians eventually forced the Romans to withdraw, the cities of Nisibis and Edessa were lost to them. The fall of Ctesiphon dealt a devastating blow to the prestige of the Arsacid dynasty among the other Parthian noble houses. In the east, the situation deteriorated further. The Kushans had wrested control of Herat and Merv, two of the wealthiest and most important cities of the region. With each successive defeat, the standing of the Arsacid family among the Parthian aristocracy grew ever more fragile. The loss of the key northern Mesopotamian cities of Nisibis and Edessa was so significant that, in 161 AD, the Parthians, for the first time in their history, became the initiators of war against Rome. Volagas IV marched into northern Mesopotamia and executed the Roman-appointed governors of Nisibis and Edessa. Despite these initial successes, his army, ravaged by plague, could not sustain its campaign against the Romans. In 165 AD, the Romans once again entered Ctesiphon, plundering the capital. Yet the same plague that had devastated the Parthian army now spread into the Roman ranks, forcing them to withdraw from the city. In 193 AD, Volagas V sought to curb Roman influence by supporting uprisings in Edessa and Adiabene. This act triggered yet another war between the In 195 AD, Emperor Septimius Severus launched an invasion of northern Mesopotamia. He secured Rome's position in Nisibis by capturing the fortress of Syngara, then marched southward and, for the third time, seized Ctesiphon, the Parthian capital. However, his forces failed to capture Hatra, and ultimately the Romans were compelled to withdraw from Mesopotamia. In 216 AD, while the Parthians were embroiled in yet another devastating civil war, the Roman Emperor Caracalla launched a massive invasion of Mesopotamia, intent on destroying the Parthian Empire once and for all. He first attacked the city of Arbella, slaughtering its inhabitants and plundering the surrounding regions. When word of the Roman advance reached Artabanus IV, he immediately set about assembling his forces. As winter approached in 217 AD, Caracalla halted his campaign and withdrew to Edessa, intending to spend the cold season behind the city's strong walls and resume his offensive in the spring. But on April 8, 217 AD, Caracalla was assassinated by his own officers and Macrinus ascended to the imperial throne. At the same time, news arrived that Artabanus was advancing toward the Roman camp with a large army. Unwilling to confront Parthian cataphracts in open battle, Macrinus sought to negotiate. He agreed to return the prisoners taken during the previous year's campaign. But Artabanus demanded more. The Romans must pay for the restoration of the cities they had devastated and they must surrender northern Mesopotamia to the Parthians. Macrinus found these terms unacceptable and the two great powers prepared for war. The Battle of Nisibis, the final confrontation between Rome and the Parthian Empire, ended in a Parthian victory. Artabanus succeeded in crushing the Roman forces, but the cost of triumph was immense. A great number of Parthian warriors fell on the field. This substantial loss significantly reduced Artabanus' military strength at a time when Persians were rapidly rising in power. After securing victory at Nisibis, Artabanus once more demanded that the Romans return the city of Nisibis. But once again, Macrinus refused. It was at this moment that the Sassanians in Paz rose in revolt, emerging as a serious threat to the Parthian Empire. With an enemy now forming behind his own lines, Artabanus softened his position in negotiations with the Romans. He abandoned his insistence on recovering the lost cities of northern Mesopotamia and, after receiving a substantial indemnity, agreed to peace. In 224 AD, Artabanus marched to the plain of Hormuzgan to confront the Persian forces. Led by Ardashir Babakan, the Persians succeeded in killing Artabanus in the midst of battle and inflicted a crushing defeat upon the Parthian army. Following this victory, Ardashir was able to reclaim the eastern territories that had slipped from Parthian control. With the eastern front now secure, his attention turned westward. Ardashir sought to wage war against the Romans, and achieve what the Arsacids had repeatedly failed to accomplish – the capture of Nisibis. In 230 AD, Ardashir marched out of Ctesiphon with his army and, in a swift and decisive offensive, succeeded in bringing the northern regions of Mesopotamia back under Persian control. Alarmed by these rapid advances, the governors of Rome's eastern provinces sent urgent messages to Emperor Alexander Severus, informing him of the Persian threat. Alexander dispatched an envoy to Ardashir with the following warning. He then reminded Ardashir of the victories of Augustus, Trajan, Verus, and Severus. Ardashir replied to the Roman Emperor. Ionia and Caria belonged to the Persians from the days of Cyrus, who first founded the Persian Empire, until Dorius fell to the accursed Alexander. It is therefore fitting that the Persians reclaim the territories of their ancient empire. In 231 AD, Ardashir crossed the Euphrates and crushed the Roman garrisons stationed in Syria. He then pushed onward into Asia Minor, destroying the Roman forces positioned in Cappadocia as well. Yet Ardashir knew that holding Syria and Cappadocia would require immense resources and could not be sustained easily. He therefore contented himself with taking spoils and returned with his troops to Ctesiphon. When news of Ardashir's advance into Syria and Cappadocia reached Alexander Severus, the Emperor began raising an army. To encourage his soldiers to face the Persians in battle, he distributed gold and silver among them. After completing the Senate's ceremonial approval, Alexander proceeded with the required sacrifices and state rituals before departing for Antioch. Upon arriving in Syria, he summoned the surviving Roman soldiers from the devastated garrisons of the region to join his camp and began preparing for the coming confrontation with the Persians. Before advancing toward Iranshahr, the Roman Emperor, hoping to resolve the crisis through diplomacy, sent an envoy to the Shahanshah of Iran. But Ardashir dismissed their request without granting them a hearing and sent them back at once. Ardashir selected 400 Persians of tall stature and strong physique, dressed them in splendid garments adorned with costly ornaments, armed them with the finest horses and bows, and sent them as envoys to the Roman camp. When the delegation was brought before the Roman Emperor, they delivered Ardashir's message. Alexander Severus, realizing that his soldiers were struck by the imposing appearance and bold demands of the Persian envoys, ordered that all 400 be immediately imprisoned. He then decreed that a tract of land in Phrygia be granted to them so that they might spend their lives in agriculture. Herodian notes that the Emperor intended that none of them should ever return to Persia. With negotiations failing in 232 AD, Alexander advanced toward the Euphrates with his massive army. Instead of marching straight toward the river, he first turned south toward Palmyra, and only afterward proceeded toward the Euphrates. He likely meant to give the impression that he intended to approach Ctesiphon from the southern route. When the Roman forces approached the Euphrates, Alexander divided his army into three columns. The first column, led by Julius Proculianus, was ordered to advance through Armenia, reconnoiter the northern regions, then enter Media and wrest it from Persian control. The second column was tasked with marching against Meshan. The third and strongest column, commanded by Alexander himself, was directed toward the very heart of the Sasanian Empire, the city of Ctesiphon. It appears that all three columns were intended to reunite at Ctesiphon, after completing their respective operations. The Emperor's strategy was clear. By forcing the numerically inferior Sasanian army to fight on multiple fronts, he hoped to weaken and disperse them. At the same time, Alexander sought to confuse the Persians regarding the direction of the main assault. For this reason, after departing Antioch, he initially turned south toward Palmyra, seemingly to create the impression that the principal Roman offensive would come from the southern route. The northern column, commanded by Julius Proculianus, crossed the winding mountain passes of Armenia and entered Media. Once inside the province, the Romans dispersed and immediately began plundering its undefended cities and villages, committing widespread looting and devastation. When news of the Roman incursion into Media reached Ardashir, he dispatched a small contingent of Aswaran, Persian heavy cavalry, to confront them. But the rugged mountainous terrain of Media prevented the cavalry from making full use of their strength, giving the Romans the advantage. They succeeded in repelling the Persian force. At the same time, word reached the Shahanshah that the other two Roman columns had crossed the Euphrates and entered Mesopotamia. Ardashir ordered his spies to observe their movements closely and report to him continuously. When intelligence arrived, showing that the southern column was advancing more rapidly and had drawn far ahead of the central column, Ardashir realized that the moment for a counter-strike had come. He now faced two options. March north to confront the central column or turn south and destroy the southern column. Believing that the southern force was the main Roman army, Ardashir departed Ctesiphon with his In the summer of 232 AD, Ardashir set out to halt the advance of the southern Roman column, which was marching toward Khuzestan. Moving with great speed, he reached them before they expected any confrontation. The Romans, not anticipating an engagement with Sasanian forces, were marching without any battle formation, believing that the central Roman column, led by Emperor Alexander himself, had already reached Ctesiphon and encircled Ardashir and his army. When Ardashir saw the disordered Roman column, he seized the moment. He ordered his horse archers to immediately encircle the enemy and destroy them under a storm of arrows. The swift Persian cavalry rode out at once, surrounding the Roman force in a tightening ring. Caught completely off guard, the Romans hastily formed a hollow square, but it was useless. Arrows rained down on them from every direction. Herodian describes the scene vividly. The king attacked it unexpectedly with his entire force and trapped the Romans like fish in a net. Firing their arrows from all sides at the encircled soldiers, the Persians massacred the whole army. While the horse archers filled the air with arrows, the Aswaran heavy cavalry charged the Roman ranks with their long lances. After each strike, they withdrew, regrouped, and charged again, attacking from every side in relentless succession. Herodian continues. Hit and wounded from every side, they held out bravely as long as they could, but in the end, all were killed. The Romans suffered a staggering disaster. It is not easy to recall another like it, one in which a great army was destroyed, an army inferior in strength and determination to none of the armies of old. The combined pressure of the mounted archers and the armoured lancers shattered the Roman formation. Hemmed in with no avenue of escape, the entire Roman column was wiped out. Thus, in their first direct encounter with the Roman Empire, the Sassanians achieved a brilliant and decisive victory. The cause of the Roman defeat lay in the lack of coordination among the three Roman columns. The main column, led by Alexander Severus himself, failed to reach Ctesiphon in time. This created a dangerous gap in the Roman advance, one that Ardashir exploited with great success, allowing him to overwhelm and annihilate the southern Roman force. Why Alexander Severus was unable to arrive on schedule remains uncertain. According to Herodian, the failure stemmed from the Emperor's inadequate ability to command an army. Nevertheless, evidence suggests that the central column was afflicted by disease and plague, slowing its march significantly. It appears that Alexander himself may have been struggling with illness. Reports of heat exhaustion among the troops further contributed to the column's reduced speed. On the opposing front, Ardashir moved promptly to exploit the disarray among the Roman ranks and struck them with effective force. One noteworthy detail recorded about this battle is that several Persian women were present on the field, fighting alongside the men. When Alexander received word of the southern column's destruction, he immediately ordered a full retreat. The northern column, still deep in the mountains of Media, suffered grievous losses during its hurried withdrawal. Some were cut down by Persian forces, while many more perished from exposure to the cold. According to Herodian, the northern column was virtually annihilated, with only a handful of survivors managing to reach safety. Thus, two of the three Roman columns were completely destroyed. After Alexander finally reached Antioch, he attempted to restore morale by distributing wealth and gifts among his shaken troops. Although Herodian's account makes the Romans' lack of success in their campaign unmistakable, the Historia Augusta presents a different narrative, one in which a great victory by Alexander is claimed. In the speech that this work attributes to Alexander, it even mentions Persian scythe chariots and an army of war elephants, an image that resembles the Achaemenid forces in their battles with the Macedonians far more than any Sasanian army. Because of this misplaced association, some Roman and Greek historians refer to Ardashir by the name Xerxes, a choice that evokes the Greco-Persian wars. Herodian notes that the Roman column on the northern front did manage to inflict certain losses on the Sasanians, yet these successes were strictly local and cannot be regarded as a decisive victory. Since the Romans failed to secure any conclusive result in this campaign, it appears that the triumphant picture presented in the Historia Augusta was largely shaped by Alexander's own political propaganda, intended to conceal the reality of what had occurred in the East. Alexander even issued coins in commemoration of his supposed victory over the Persians and organized a public celebration in Rome to mark his triumph. Despite the Roman defeat, Ardashir, whose army had also suffered losses, was unable to continue the war against Rome. He used the temporary calm restored along his western frontier to launch another campaign into Armenia. According to Armenian historians, Ardashir invaded Armenia but failed to achieve success and therefore resorted to treachery. He had Khosrov, the Armenian king, assassinated and thus brought Armenia under his authority. Ardashir then ordered a rock relief to be carved in Armenia to commemorate his victory. Nevertheless, other evidence suggests that Sasanian control in Armenia did not last and that the Arsacid dynasty soon managed to regain power. From the moment Ardashir seized authority in Darabgerd to the time he defeated Alexander and entered Armenia, he had been engaged almost continuously in military campaigns. When a period of relative peace finally emerged, he turned to the restoration and reconstruction of the regions devastated by the recent wars. He dismissed the soldiers who had fought beside him for decades so they could return to their homes and families. In 235, when news of the death of the Roman emperor Alexander Severus reached Ardashir's court, he judged the moment suitable to resume hostilities with Rome. In the next episode, we will examine the final years of Ardashir, the first Sasanian Shahanshah.