Picture a great fissure in the earth that opens on the Arabian shores of the Red Sea and terminates at the mountains of Armenia. These were the bounds that separated the Roman world from that of its great adversary, the Persian Empire, in the 4th century AD.
On the eastern side, Persia flourished under the Sassanid dynasty for over four centuries at the beginning of the Common Era. It was, in the words of Emperor Julian, the traditional enemy of Rome.
The Sassanians witnessed the decline of the Roman Empire from their sultry Mesopotamian homeland. And by the time of the fall, the Persian Empire was poised to absorb a significant portion of its former territory.
But while Rome still had integrity, it managed to keep them at bay. And on one occasion it even penetrated deep into Persian territory and threatened the very existence of the Sassanid kings, namely Julian’s Persian War and its decisive Battle of Ctesiphon.
For all his letters on the importance of philosophy, Julian still had temporal ambitions. He viewed himself as both a stalwart of the classical world and a modern Alexander: this identity drove him to attempt to restore the values of Hellenism, stifle the spread of Christianity, and expand Roman territory far beyond the empire’s existing borders. So in 363 AD he set out to conquer the entirety of Persia in a matter of three months—a feat so ambitious that no other Roman emperor had ever achieved it.
The Battle of Ctesiphon was the capstone of that campaign. It was in this epic clash that Julian, leading a vanguard of Gallic Romans and Asiatic Christians, defeated Shapur II, the Great King of Persia, outside the walls of his magnificent Mesopotamian capital.
Winter 363 AD: Battle Plans And The March From Antioch
By January 363, Julian Augustus had taken residence in the Greek city of Antioch. It was here that he devised grand plans for the forthcoming Persian War—a war that Julian deemed necessary to put an end to Shapur’s harassment of Rome’s eastern borderlands. A decision that would eventually lead to the battle of Ctesiphon.
In ancient times, Antioch was synonymous with luxury and vice. It was constructed by Seleucus I, a contemporary of Ptolemy I and fellow member of Alexander’s Diadochi. Antioch became the seat from which the Seleucid Empire controlled the Near East for three hundred years before it fell to the Romans. Seleucus was the first to plant cypress groves in the nearby pleasure gardens of Daphne that surrounded the sanctuary of Apollo, a legendary place that was nearly defunct by the time of Julian’s visit.
The Queen of the East, as Antioch was called, exuded wealth and beauty: it was decorated with miles of Tiberian porticoes and ensconced behind elaborate gates of Egyptian granite. And its profligate citizenry had traditionally preferred gambling and sex to serious religion.
But by the time Julian had arrived there, Antioch was in a precarious state similar to that of many other cities across the empire. After two consecutive Christian emperors, Constantine the Great and Constantius II, the Christian establishment had made significant inroads in Rome.
And by the mid-4th century, temples dedicated to the ancient gods were mostly in disrepair. Christianity had found a home in the hearts of thousands of zealous converts, most of whom had ill will toward the apostate emperor. But Julian was determined to honor the classical past nonetheless.
Before embarking for Persia, he trekked to Daphne to make sacrifices to the sun god. He sent a delegate to Rome to consult the Sibylline Books—an assemblage of oracular maxims that predated the Roman Republic. And he made contact with the oracles at Delphi and Delos to obtain their blessings.
The omens were mostly bad. Their answers were almost uniformly the same: it would be unwise for the emperor to enter Persia during that calendar year.
But Julian was obstinate and known for reinterpreting unfavorable forecasts to his own liking. So on March 5, 363, he embarked from Antioch due east toward Persia to the first military rendezvous point, a Roman city called Carrae on the southern border of modern-day Turkey.
Here he sent his cousin and 30,000 Roman troops on a mission to Armenia with the diversionary task of joining forces with that country’s king to attack the Persian Empire from the north.
Then the Roman legions moved southward along the Euphrates River to a different Roman city called Callinicum.
The Euphrates, which today continues to be an important geopolitical landmark, was essential to the plan: from Callinicum the Romans would track the river, sacking each Persian settlement as they passed, until they reached Ctesiphon, the capital of the Great King Shapur.
Speed would have to be the modus operandi. And, luckily, Julian, who could move armies faster than any other, would be their trailblazer.
Spring 363 AD: The Romans Ravage Persia
It was March 27, the festival of the great mother Cybele, when Julian and his host of 60,000 reached Callinicum. He made sacrifices to the goddess and awaited the arrival of his naval fleet.
Assembled around him was a campaign entourage as eclectic as the emperor himself. There were Gallic warriors from his days as Caesar in the west, philosophers from his youth as a student in Athens, and Etruscan priests that he kept on retainer to interpret omens. There was an exiled Persian prince, a certain Hormizd, with whom Julian planned to replace Shapur after his deposition. But mostly, there were Asian generals, almost entirely Christian and from the court of Constantinople—many of whom secretly despised the emperor.
However, his innermost circle consisted of two notable characters: (1) a certain Maximus of Ephesus, a mystic priest who had initiated him into the Eleusinian Mysteries—the illustrious rites of the cult of Demeter and Persephone. And (2) one Priscus of Epirus, a Neoplatonist with whom Julian had studied during his youth in Athens. A fellow philosopher, Priscus became Julian’s right-hand man and most trusted adviser after he was crowned Augustus of the Roman Empire.
The naval fleet was late at Callinicum, and so the legions moved south to their last post within Roman territory.
On April 3, the fleet arrived in Circesium: it amounted to 50 warships and 1,400 cargo boats filled with weaponry and food supplies. Every inch of the Euphrates was occupied by Roman vessels equipped to unleash hell on the Persian Empire. So the lightning campaign began.
And upon the first day of marching on foreign territory, a great lion was killed, which, to Maximus, portended the death of a king. He was certain it would be Shapur; Julian wasn’t convinced.
That evening, Mastara, High Priest of the Etruscans, also prophesied the death of a king from a lightning strike that he interpreted as a sign from Ares, the god of war. Though, exactly which king, he admitted, was unclear.
Julian sacrificed fervently—to Helios, to Zeus, to Cybele. He asked for the intercession of those gods for whom he worked tirelessly to restore throughout Rome and planned to introduce to the barbarian of the Persian Empire.
But his anxieties were soon quelled by victory: on April 15, the Romans captured their first city on the Euphrates, Anatha. Just over 100 miles into Persian territory, the city surrendered upon the terrifying sight of the oncoming Roman host.
As a result, morale was high. And it was only bolstered by the following events. A slew of cities and fortresses south of Anatha—Thilutha, Achaiachalca, Baraxmalchia, and Diacira—were either abandoned or surrendered without a struggle. At each new settlement, Hormizd, every bit the Persian dignitary, would saunter into the governor’s palace to negotiate Julian’s terms.
It wasn’t until Macapracta, a city within range of Ctesiphon, that the Roman legions first experienced Persian resistance.
Summer 363 AD: The Battle Of Ctesiphon
On April 23, Persian cavalry led by Shapur’s Grand Vizier confronted the Roman legions outside this city. Julian went on the offensive and repelled them with limited casualties. Then the Romans continued on at lighting speed, laying siege to and capturing the remaining settlements between Macapracta and Ctesiphon.
And in May, they reached the hinterlands of the capital where the legions seized Shapur’s luxuriant countryside estates. This region of Mesopotamia, in the neighborhood of modern-day Baghdad, is detailed in Julian’s wartime journal as a lush, green land abundant with orchards and date groves—a final reprieve for the Romans before the Battle of Ctesiphon.
On May 24, in an effort to approach Shapur’s host from the most advantageous position, Julian ordered the reopening of Trajan’s Canal. The imprint of a deep channel between the Euphrates and Tigris rivers, originally dug by its namesake during his Parthian War in 113 AD, was still visible.
And when Julian’s engineers had successfully opened it, the Romans sailed into the Tigris, putting themselves squarely in range of the Persian Empire’s capital.
At the banks of the river there was a great, flat stretch of land that terminated at the base of the high walls of Ctesiphon. It was here that the Grand Vizier awaited the Romans with all the forces that the Persian Empire could muster.
There were innumerable cavalry and infantry rows, and behind them, 100 war elephants fastened with iron towers holding archers. Shapur and his retinue of attendants presided over the spectacle from the shade of a marquee atop the city’s walls.
The Battle of Ctesiphon raged for 12 straight hours, from sunrise to sun down on May 27. And the Romans, high off the successes of their lightning campaign in Mesopotamia, held the field the whole time.
According to Roman sources, the difference in character between the two armies was significant. For one, the Grand Vizier commanded his forces from the security of a war elephant just outside the city gates. Julian, on the other hand, led the vanguard that had initially taken the riverbank of the Tigris. And then he led the charge into battle at the city’s walls.
The Persian forces served by means of coercion. While many of the Romans, especially the Gallic legions, loved their leader and genuinely believed in his cause.
By the midway point of the battle, the Romans had breached the ranks of Persian infantry and Shapur’s elephants were in a rout. They stampeded recklessly, crushing Persians and Romans alike. Before sunset, the city gates were flung open and the Grand Vizier called a retreat. The Persian host fled the battlefield in disgrace.
The Battle of Ctesiphon resulted in 2,500 dead Persians to only 75 Romans. Shapur had lost the entire heartland of his empire in a matter of two months, and now, barricaded in his capital city, he was in a position of embarrassing defeat.
Aftermath Of The Battle Of Ctesiphon
The Great King sent Julian an emissary who outlined his terms of surrender. In addition to paying the full cost of the Persian War, he would relinquish a huge swath of northern Mesopotamia to Rome.
It was entirely favorable for the Romans, but Julian declined nonetheless. And his refusal to accept Shapur’s terms is, in retrospect, a lesson in hubris. He wanted to achieve a level of greatness tantamount to that of Alexander. And, foolishly considering that the Battle of Ctesiphon had crippled the Persians, he decided to continue his conquest of the remainder of Mesopotamia.
His heart was set on reaching the Persian Gulf. So, instead of laying siege to Ctesiphon, the Romans proceeded due southeast. The Persians, however, knew their country far better than Julian. And between supply lines being disturbed and Persian guerilla tactics of field burning, the Roman army nearly starved in southern Mesopotamia.
Worse, the reinforcements from Armenia never arrived as anticipated. Hormizd, who could almost taste the Persian throne in May, now envisioned his more likely future as a permanent exile in Constantinople.
Julian begrudgingly terminated his campaign in June, and his victory at the Battle of Ctesiphon turned into a costly defeat. And on June 26, somewhere in the backwater of northern Persia, the exhausted Roman host was ambushed by the forces of the Grand Vizier. In the chaos of battle, Julian was struck by a spear and died.
It was only later discovered that he was killed by a member of his own ranks—a Christian general who resented his apostasy. A young Pannonian soldier named Jovian was made emperor in his stead. He restored Christianity as the official religion of the empire and had Maximus imprisoned for practicing magic. Later, he executed him.
Priscus was forced to go back in the closet, so to speak, about his affection for classical philosophy. He spent the remainder of his life hiding out in Athens.
Had Julian accepted Shapur’s original terms and returned to Constantinople after the Battle of Ctesiphon, the ensuing history of Europe might have been different. During his three short years as emperor, Hellenism was reemerging from the shadows. And Christian intolerance was put in check. The Battle of Ctesiphon was decisive, but the decisions made after it were even more so.