Roman Mesopotamia - 163-363 - From L. Verus to Jovian

Hadrian abandoned Trajan's forward policy in 117 AD in favor of a Euphrates boundary. Under M.Aurelius, Mesopotamia was again conquered by L. Verus (163-165), as far as the Median Wall (S. Rufus, Brev. 14); and the conquest was further secured by the foundation of the colonies of Carrhae on the Chaboras and Singara, to which Septimius Severus added those of Nisibis and Rhesaena. But this province was a constant cause of war between the Persian and Roman empires; and at length the greater part of it was surrendered to the Persians by Jovian in AD 363.

The division of the Roman Empire among three Emperors after Constantine's death, and the outburst of licentiousness and violence among the Roman soldiery in the imperial capital and in the Eastern Roman provinces, gave Sapor II. high hopes of success; while the distracted condition of Armenia was also such as to encourage the Persian king. Sapor II set the Arabs and Armenians in motion; exciting the pagan party in Armenia to revolt, to deliver their king, Tiranus, into his power, and to make raids into the Roman territory, while the Arabs ravaged the Roman provinces of Mesopotamia and Syria. Sapor II. himself won moderate successes during the first year of the war (A. D. 337). Constantius II. gained some advantages; restoring the direction of affairs in Armenia to the party friendly to Rome, winning some of the Mesopotamian Arabs from the Persian to the Roman side, and even erecting forts in Persian territory on the east side of the Tigris.

The next year (AD 338) Sapor II, resolved upon recovering Mesopotamia, overran and ravaged that Roman province, plundering the crops, driving off the cattle, and burning the villages and homesteads. He laid siege to the strongly fortified city of Nfsibis, the Nazibfna of the Assyrians, and the most important town of Mesopotamia under the Romans. After a gallant defense by the Roman garrison and the inhabitants, who were sustained by the prayers and exhortations of its Christian bishop, St. James, the Persian king was repulsed with heavy loss and forced to raise the siege, which had lasted two months.

In AD 350 the Roman Emperor was recalled from Mesopotamia to the West of Europe to contend against two rival pretenders to the imperial throne, and the Persian king was summoned to his north-eastern frontier to repel a Scythian invasion. War-ridden Mesopotamia was now given a breathing-spell to recover from the ruin and desolation which had overwhelmed it.

The Romans very much desired a more settled and formal peace than the precarious truce which Mesopotamia had been permitted to enjoy for the last five or six years. Two great Roman officials, Cassianus, Duke of Mesopotamia, and Musonianus, Praetorian Prefect, had considered the time favorable for ending the provisional truce in Mesopotamia by a definite peace, as Sapor II. was engaged in a bloody and difficult war at the eastern extremity of his dominions, while the Emperor Constantius II. was fully occupied with the troubles occasioned by the barbarian inroads into the more western Roman provinces.

In AD 359 another war broke out between the Roman and New Persian Empires. A Roman army occupied Mesopotamia and advanced to the Tigris, laying waste the country as the Persians advanced, destroying the forage, relinquishing the indefensible towns to the Persians, and fortifying the Euphrates with castles, military engines and palisades. The swell of the Euphrates prevented the Persians fording the river at the usual point of passage into Syria. By the advice of Antoninus, Sapor marched to the Upper Euphrates, defeated the Romans near Amida, now Diarbekr, and took two castles which defended the town.

The campaign of AD 359 ended with this costly victory, and Sapor retired across the Tigris without leaving any garrisons in Mesopotamia. He prepared for the next year's campaign, accumulating stores of all kinds during the winter; and in the spring of A. D. 360 he again invaded the Roman province of Mesopotamia with a larger and betterorganized army than the one with which he took Amida the year before. Constantius II. died near the close of the year AD 361; whereupon Julian the Apostate became sovereign of the vast Roman Empire. Sapor II found Julian a far abler antagonist than Constantius II had been. The Roman Emperor received offers of assistance from the independent or semi-independent princes and chieftains of the regions bordering on Mesopotamia; but Julian rejected these overtures, saying that it was for Rome rather to give aid to her allies than to receive assistance from them.

When the Roman army arrived on the fertile alluvium of Babylonia, the Persians changed their passive attitude and began an active system of perpetual warfare. Julian, who was an able soldier as well as a man of some intellectual culture, undertook the hazardous enterprise of invading the East, and he penetrated as far as the regions about the Tigris. He gained'some successes, but though a professed philosopher, he followed them up with the merciless cruelty of a savage. In one city which he captured, Maogamalcha, a miserable remnant of the inhabitants were actually hunted out of caves and cellars by means of smoke and fire.

Julian continued his march along the Euphrates, while the dashes Julianas of the Persian cavalry caused him some sensible losses. He finally came to the point where the Nahr-Malcha, or "Royal River," the principal canal connecting the Euphrates with the Tigris, branched off from the Euphrates and ran almost directly east to the vicinity of Ctesiphon. The canal was navigable by the Roman ships, and the Emperor therefore directed his march eastward along the canal, following the route taken by Septimius Severus in his expedition against the Parthians, a century and a half before. As the Persians flooded the country with water and disputed his advance at every favorable point, his progress was slow and difficult; but by felling the palms which grew so abundantly in this famous region, and forming them into rafts supported by inflated skins, Julian was able to pass the inundated region.

Julian led his troops against the Persians and engaged in a hand-to-hand struggle from morning until noon, when the Persians fled. Their leaders—Tigranes, Narseus and the Surena— were the first to leave the field and take refuge within the defenses of Ctesiphon. The entire Persian army then abandoned its camp and baggage, and rushed across the plain in the wildest confusion to the nearest of the gates of Ctesiphon; being closely pursued by the victorious Romans to the very walls of the city. Thus the entire Persian army was defeated by one-third of the Roman army under the Emperor Julian.

As the route along the Euphrates and the Nahr-Malcha had been exhausted of its supplies and its forage, and its towns and villages desolated, Julian ordered the retreat through the fertile country along the east bank of the Tigris, and the army to spread over the productive region to obtain ample supplies. The march was to be directed on the rich Roman province of Cordyene (now Kurdistan), about two hundred and fifty miles north of Ctesiphon. The retreat began June 16, AD 363. No sooner had the Roman army been set in motion than an ominious cloud of dust on the southern horizon appeared, and grew larger as the day advanced. Julian at once knew that the Persians were in full pursuit. At dawn on June 26, AD 363, the Roman army struck its tents Battle of and resumed its retreat across the wasted plain along the east side of the Tigris. Near Samarah the Roman rearguard was violently assailed by the Persians. Julian was mortally wounded, and the Romans could but barely claim anything of a victory. Sapor now pressed on them, and made their retreat difficult.

Jovian, Julian's successor, was soon glad to accept terms of peace, though they were of such a kind that Ammianus Marcellinus, a contemporary writer who served in Julian's army, Ammianus declares it would have been better to have fought ten battles than to have made such shameful concessions. It is certain, however, that the Roman army was in the utmost peril. Rome had to give up all territory to the east of the Tigris, with Nisibis and Singara, strong positions in eastern Mesopotamia, and also to break off all connection with Armenia, which she liked to look upon as a dependency. This was a great blow to Roman prestige in the East.