Shapur II of Persia ruled his nation for most of the fourth century, from 309 - 379 C.E. He helped restore Persian power, which had gone into serious eclipse in the latter part of the third and early fourth centuries. It was largely thanks to Shapur's ambition and energy that Persia again became a dangerous enemy for the Eastern Romans. It would retain that status until the Sassanian state finally collapsed before the advance of the Arabs in the second quarter of the seventh century.

Head of a Sassanian Ruler (believed to be Shapur II, 309-373 C.E.), from the collection of the Metropolitan Museum, New York

Shapur II was the posthumous son of his father, Hormizd II. Thanks to a curious set of circumstances, which plainly intrigued and inspired Gibbon, he was acknowledged as the ruler of his country before he was actually born:

"Although Shapour was in the thirtieth year of his long reign [in 339], he was still in the vigor of youth, as the date of his accession, by a very strange fatality, had preceded that of his birth. The wife of Hormouz remained pregnant at the time of her husband's death; and the uncertainty of the sex, as well as of the event, excited the ambitious hopes of the princes of the house of Sassan. The apprehensions of civil war were at length removed, by the positive assurance of the Magi that the widow of Hormouz had conceived, and would safely produce, a son. Obedient to the voice of superstition, the Persians prepared, without delay, the ceremony of his coronation. A royal bed, on which the queen lay in state, was exhibited in the midst of the palace; the diadem was placed on the spot which might be supposed to conceal the future heir of Artaxerxes, and the prostrate Satraps adored the majesty of their invisible and insensible sovereign."

Gibbon adds that "we must admire not only the fortune, but the genius, of Sapor. In the soft sequestered education of a Persian harem, the royal youth could discover the importance of exercising the vigour of his mind and body; and, by his personal merit, deserved a throne, on which he had been seated while he was yet unconscious of the duties and temptations of absolute power."

Shapur II Hunting, from the collection of the Hermitage Museum in St. Petersburg

During Shapur's minority (he came of age at sixteen years), Persia was governed by a regency, with various competing factions vied for power. The internal turmoil became so severe that the king of Yemen was able to launch a successful raid across the entire breadth of the Arabian peninsula that surprised and captured the Persian capital of Ctesiphon. He plundered the city and carried off one of Shapur's aunts into captivity with him when he returned to his own distant corner of Arabia.

Ruins of the Palace of Shapur I (241-272 C.E.) at Ctesiphon

Such slights as these doubtless helped fire young Shapur's ambition, but he seems to have been particularly keen to avenge his grandfather Narses's humiliating defeat by Diocletian in 297 C.E., which had resulted in the cession of five Persian provinces in upper Mesopotamia to the Romans. The continuation of Roman rule over these provinces was not only a national humiliation; it also severely compromised the security of the Sassanian state. Roman strongholds like Singara (Sinjar) and Bezabde (Jezireh) in northern Mesopotamia served as advance bulwarks of the Empire, greatly strengthening its defenses against possible Persian incursions while simultaneously ensuring that the Persian capital remained strikingly vulnerable to aggressive Roman thrusts launched down the valleys of the Euphrates or Tigris Rivers.

Although the first phase of the war between Constantius and Shapur II lasted for thirteen years, from 337-350 C.E., our sources for the period are sketchy and incomplete, throwing only a fitful light upon the course of events. Not surprisingly, it was Shapur, as the party dissatisfied with the status quo, who was the most aggressive, while Constantius sensibly followed a defensive strategy that took full advantage of the strength of the Roman border fortresses and the often inhospitable desert terrain.

Much of the fighting over the next quarter century swirled around a quartet of Roman legionary fortresses in northern Mesopotamia and the upper Tigris basin: Amida (modern Diyabakir in Turkish Kurdistan), Bezabde (now an unoccupied site near Cizre [Jezireh] on the Tigris in far northeastern Syria), Singara (Sinjar, in Iraq), and Nisibis (Nusaybin, a sleepy Turkish border town on the frontier with Syria). During the first round of the war, it was Nisibis that bore the brunt of the Persian assaults. Originally founded by Seleucus I Nicator to provide a home for demobilized veterans of Alexander the Great's campaigns, Nisibis guarded a crossing point over the Mygdonius River a few miles south of the great escarpment running east and west that marks the northern limit of the Syrian and Mesopotamian desert.

To see three views of the Church of Mar Yakub at Nisibis, taken by the British archaeologist and antiquarian Gertrude Bell in 1911, click here, here, and here. The oldest surviving portion of the church is the baptistery at its southeastern corner, built in 359. The crypt of the baptistery contained the tomb of Mar Yakub.

Nisibis owed its prosperity to the caravan trade attracted by its bazaar and to its status as a fortress town. The city was strongly defended by a triple circuit of brick walls and a deep ditch and served as the military headquarters of the Dux Mesopotamiae. During the first four decades of the fourth century, however, the city was dominated by the strong personality of its first bishop, Mar Yakub (Jacob or James). He assumed his position in Nisibis sometime in the early 300's. By 312, the year Constantine defeated Maxentius north of Rome at the Battle of the Milvian Bridge, the city's Christian population had grown sufficiently that Mar Yakub commenced construction of the city's first cathedral, which was finished eight years later. It was probably a boxy and barnlike basilica, strongly built of great blocks of stone (it apparently stood for at least four hundred years), but not altogether without some touches of grace and ornamentation: we know from John Moschos's The Spiritual Meadow of the late sixth century that it had five arches across its front portal, where the city's poor congregated to beg for alms. The Dux Mesopotamiae maintained a palace on the citadel mound in the southern part of the city, and late antique Nisibis apparently had a colonnaded main street leading to the marketplace. A few poor fragments of the colonnade still stand today, in the shadow of the border wire that marks the Turkish-Syrian frontier.

To see the remains of the colonnade at Nisibis, click here.

Shapur initiated hostilities in the late spring or early summer of 338. The Sassanian army moved first against Nisibis, from whence roads led west towards the crossing of the Euphrates at Zeugma and northward into Armenia. This initial Persian siege lasted two months, during which the now elderly Mar Yakub distinguished himself by his courage and energy as he rallied the citizens in a vigorous and ultimately successful defense. When the noble bishop died not long afterwards, the grateful citizens of Nisibis transformed his tomb into the chief shrine of their town.

Frustrated on the central front, Shapur intervened in Armenia. A conspiracy was formed against King Tiran by his chamberlain, the Governor of Atropatene, and one of the other provincial governors, who objected both to Tiran's pro-Roman orientation and his christianizing policy. Tiran was seized by the conspirators and turned over to the Persians, who blinded him. His son Arshak fled to Constantius for support, while behind him the pro-Persian party murdered or expelled the Christian priests, who were seen as a pro-Roman fifth column.

Three years later, a Roman army under Count Antiochus invaded the country and restored Arshak to his father's throne. But this success did not materially alter the military balance, for the prudent Arshak recognized that his country's independence and his own authority required him to maintain a skillful balancing act between his two immensely powerful neighbors. Thus, having first married Olympias, a Greek lady who was somehow connected with the House of Constantine, during his time in exile, upon her death Arshak agreed to marry a daughter of King Shapur, and thereafter pursued a neutral policy with regard to his neighbors' war.

Both sides competed with gold payments for the loyalty of the Arabs tribesmen of Syria and Arabia. Those in the pay of Persia sometimes raided as far as the outskirts of Constantius's capital of Antioch, while others in the Romans' service mounted similar operations against the heartland of the Sassanian realm between the two great rivers of Mesopotamia.

Constantius worked hard to improve the quality of the Roman forces in the east. He demanded additional contributions from all the eastern provinces and enlarged the flotillas that guarded the upper reaches of the Tigris and the Euphrates. In imitation of the Persians, Constantius also organized a troop of mail-clad horsemen, the first of the famous cataphracti who would ultimately replace the legions and become the backbone of the Byzantine army from the time of Justinian forward.

The historian Eutropius tells us that this first phase of the war was marked by nine great battles, in two of which Constantius personally commanded the Roman side. But we have detailed information about only one of these sanguinary engagements: the Battle of Singara, which most historians now believe occurred in the summer of 344 C.E.

To see a view of the desert landscape near Singara [Sinjar], click here.

Shapur had assembled a massive army behind the Tigris in the spring of that year, and Constantius moved east with his own forces to meet the expected attack. When Shapur's forces began crossing the river in three divisions, Constantius ordered the frontier guards not to contest his passage, but to fall back across the desert to join his main force. Constantius took up a position not far from the oasis town of Singara, which occupies an isolated position amidst the gravel deserts and furnace-like heat of north-central Mesopotamia. Shapur brought his massive army forward, and constructed an immense fortified camp around another set of springs nearby at Hileia. The Roman historians record that Shapur's army, when drawn up for battle, was so numerous that its front extended a distance of twelve miles.

The battle began in the morning and continued for the rest of the day. In mid-afternoon, a portion of the Persian front broke and went streaming back in disorder towards their camp, where a line of cataphracti had been posted in reserve. The Roman infantry, fainting from their exertions beneath the broiling mid-summer sun, followed up the fugitives with an aggressiveness that may have owed more to the knowledge that there were springs inside the enemy's ramparts than from the more traditional desire to loot his camp. Constantius, concerned about the lateness of the hour and the presence of undefeated enemy forces near at hand, tried to rein in his troops, but without success. The Roman legionaries cut down the Persian cataphracts posted in front of the camp, filled the ditch, and overwhelmed the archers posted atop its ramparts. As the Persian resistance collapsed, the Romans dispersed throughout the enemy camp, thinking only of water and the riches to be gained as the reward of their victory. Shapur fled towards the Tigris; the Persian crown prince, less fortunate, was taken prisoner inside the camp, tortured, and then executed by his captors.

The Roman victory seemed complete. With the passage of a few hours, however, one of Shapur's generals recovered his nerve. As the Romans gave themselves heedlessly over to ransacking the camp in quest of valuables, the Persians stealthily advanced a large force of archers under the cover of darkness. The fires burning inside the looted camp illuminated their target, and suddenly masses of arrows poured out of the night sky, striking down hundreds inside the ramparts and sending the survivors fleeing in their own turn. The defeat blunted Shapur's striking force, however, and the following day his army again withdrew beyond the Tigris.

Another significant aspect of the war was that it was soon acquired the character of a religious as well as a political contest. Although the Persian kings were closely identified with the state religion of Zoroastrianism, Christianity had become widely diffused throughout the Empire and was particularly prevalent in the great Mesopotamian caravan cities. Shapur came to fear that the Christians represented a potential pro-Roman fifth column inside his domains, and he ordered that all Christians should be forcibly converted on pain of death if they refused. This persecution was marked by such incidents as the martyrdom of St. Barbasymas, the bishop of Seleucia and Ctesiphon, together with sixteen of his priests in 342.

Four years after the Battle of Singara, Shapur again advanced against Nisibis, and this time the city successfully sustained a siege of eighty days. Finally, in the spring of 350, Shapur mounted his greatest effort yet. Nisibis was defended by Count Lucilianus, Duke of Mesopotamia, and perhaps was guarded as well by the beloved spirit of Mar Yakub. For the dramatic incidents of this final siege, we turn again to Gibbon:

"The event of the two former sieges elated [the defenders'] confidence, and exasperated the haughty spirit of the Great King, who advanced a third time towards Nisibis, at the head of the united forces of Persia and India. The ordinary machines invented to batter or undermine the walls were rendered ineffectual by the superior skill of the Romans; and many days had vainly elapsed, when Sapor embraced a resolution, worthy of an eastern monarch, who believed that the elements themselves were subject to his power. At the stated season of the melting of the snows in Armenia, the river Mygdonius, which divides the plain and the city of Nisibis, forms, like the Nile, an inundation over the adjacent country. By the labour of the Persians, the course of the river was stopped below the town, and the waters were confined on every side by solid mounds of earth.

To see a view of the ancient bridge over the Mygdonius at Nisibis, click here.

"On this artificial lake, a fleet of armed vessels, filled with soldiers and with engines which discharged stones of five hundred pounds weight, advanced in order of battle, and engaged, almost upon a level, the troops which defended the ramparts. The irresistable force of the waters was alternately fatal to the contending parties, till at length a portion of the walls, unable to sustain the accumulated pressure, gave way at once, and exposed an ample breach of one hundred and fifty feet.

"The Persians were instantly driven to the assault, and the fate of Nisibis depended upon the event of the day. The heavy armed cavalry, who led the van of a deep column, were embarrassed in the mud, and great numbers were drowned in the unseen holes which had been filled by the rushing waters. The elephants, made furious by their wounds, increased the disorder, and trampled down thousands of the Persian archers. The Great King, who, from an exalted throne, beheld the misfortunes of his arms, sounded, with reluctant indignation, the signal of the retreat, and suspended for some hours the prosecution of the attack. But the vigilant citizens improved the opportunity of the night; and the return of day discovered a new wall of six feet in height, rising every moment to fill up the interval of the breach."

Shapur had now been battering against the walls of Nisibis for four months at a cost of more than 20,000 Persian lives. Still, he remained determined to press the siege to a victorious conclusion, but fate determined otherwise. Persia, like Rome, had to deal with periodic barbarian incursions, and now a massive invasions of the barbarian Massagetae forced Shapur to reluctantly raise the siege of Nisibis and march with his forces to the opposite end of his domains to counter this new enemy on the Oxus River in what is today northern Afghanistan. As Gibbon writes, "The danger and difficulties of the Scythian war engaged him soon after to conclude, or at least to observe, a truce with the Roman Emperor that was equally grateful to both princes; as Constantius himself, after the deaths of his two brothers, was involved, by the revolutions of the west, in a civil contest, which required and seemed to exceed the most vigorous exertion of his undivided strength."

Coin Portrait of Shapur II [If you're interested in seeing other Sassanian coins, offered for sale at a reasonable price, visit here.]

The "civil contest" to which Gibbon alludes was the usurpation, in January 350, of the Western Empire by the Frankish general Magnentius. We therefore must now conclude the story of the promising rise and shameful fall of Constans, the youngest of Constantine's sons.

Sources:

Gertrude Bell, The Churches and Monasteries of the Tur Abdin (1982 Reprint ed.), at 70-73

Edward Gibbon, The Decline & Fall of the Roman Empire ((J.B. Bury ed.), Volume II, at 237-44 and 591-92

H.M. Gwatkin & J.P. Whitney, eds., The Cambridge Medieval History: Volume I: The Christian Roman Empire and the Foundation of the Teutonic Kingdoms (1967), at 57-60

T.A. Sinclair, Eastern Turkey: An Architectural and Archaeological Survey, Volume III (1989), at 342-345