Position of Affairs on the Death of Constantine. First War of Sapor with Rome, A.D. 337-350. First Siege of Nisibis. Obscure Interval. Troubles in Armenia, and Recovery of Armenia by the Persians. Sapor's Second Siege of Nisibis. Its Failure. Great Battle of Singara. Sapor's Son made Prisoner and murdered in cold blood. Third Siege of Nisibis. Sapor called away by an Invasion of the Massagatae.
"Constantius adversus Persas et Saporem, qui Mesopotamiam vastaverant, novem prasliis parum prospere decertavit."—Orosius, Hist. vii. 39.
The death of Constantine was followed by the division of the Roman world among his sons. The vast empire with which Sapor had almost made up his mind to contend was partitioned out into three moderate-sized kingdoms. In place of the late brave and experienced emperor, a raw youth, who had given no signs of superior ability, had the government of the Roman provinces of the East, of Thrace, Asia Minor, Syria, Mesopotamia, and Egypt. Master of one third of the empire only, and of the least warlike portion, Constantius was a foe whom the Persian monarch might well despise, and whom he might expect to defeat without much difficulty. Moreover, there was much in the circumstances of the time that seemed to promise success to the Persian arms in a struggle with Rome. The removal of Constantme had been followed by an outburst of licentiousness and violence among the Roman soldiery in the capital; and throughout the East the army had cast off the restraints of discipline, and given indications of a turbulent and seditious spirit. The condition of Armenia was also such as to encourage Sapor in his ambitious projects. Tiridates, though a persecutor of the Christians in the early part of his reign, had been converted by Gregory the Illuminator, and had then enforced Christianity on his subjects by fire and sword. A sanguinary conflict had followed. A large portion of the Armenians, firmly attached to the old national idolatry, had resisted determinedly. Nobles, priests, and people had fought desperately in defence of their temples, images, and altars; and, though the persistent will of the king overbore all opposition, yet the result was the formation of a discontented faction, which rose up from time to time against its rulers, and was constantly tempted to ally itself with any foreign power from which it could hope the re-establishment of the old religion. Armenia had also, after the death of Tiridates (in A.D. 314), fallen under the government of weak princes. Persia had recovered from it the portion of Media Atropatene ceded by the treaty between Galerius and Narses. Sapor, therefore, had nothing to fear on this side; and he might reasonably expect to find friends among the Armenians themselves, should the general position of his affairs allow him to make an effort to extend Persian influence once more over the Armenian highland.
The bands of Sapor crossed the Roman frontier soon after, if not even before, the death of Constantine; and after an interval of forty years the two great powers of the world were once more engaged in a bloody conflict. Constantius, having paid the last honors to his father's remains, hastened to the eastern frontier, where he found the Roman army weak in numbers, badly armed and badly provided, ill-disposed towards himself, and almost ready to mutiny. It was necessary, before anything could be done to resist the advance of Sapor, that the insubordination of the troops should be checked, their wants supplied, and their good-will conciliated. Constantius applied himself to effect these changes. Meanwhile Sapor set the Arabs and Armenians in motion, inducing the Pagan party among the latter to rise in insurrection, deliver their king, Tiranus, into his power, and make incursions into the Roman territory, while the latter infested with their armed bands the provinces of Mesopotamia and Syria. He himself was content, during the first year of the war, A.D. 337, with moderate successes, and appeared to the Romans to avoid rather than seek a pitched battle. Constantius was able, under these circumstances, not only to maintain his ground, but to gain certain advantages. He restored the direction of affairs in Armenia to the Roman party, detached some of the Mesopotamian Arabs from the side of his adversary, and attached them to his own, and even built forts in the Persian territory on the further side of the Tigris. But the gains made were slight; and in the ensuing year (A.D. 338) Sapor took the field in greater force than before, and addressed himself to an important enterprise. He aimed, it is evident, from the first, at the recovery of Mesopotamia, and at thrusting back the Romans from the Tigris to the Euphrates. He found it easy to overrun the open country, to ravage the crops, drive off the cattle, and burn the villages and homesteads. But the region could not be regarded as conquered, it could not be permanently held, unless the strongly fortified posts which commanded it, and which were in the hands of Rome, could be captured. Of all these the most important was Nisibis. This ancient town, known to the Assyrians as Nazibina, was, at any rate from the time of Lucullus, the most important city of Mesopotamia. It was situated at the distance of about sixty miles from the Tigris, at the edge of the Mons Masius, in a broad and fertile plain, watered by one of the affluents of the river Khabour, or Aborrhas. The Romans, after their occupation of Mesopotamia, had raised it to the rank of a colony; and its defences, which were of great strength, had always been maintained by the emperors in a state of efficiency. Sapor regarded it as the key of the Roman position in the tract between the rivers, and, as early as A.D. 338, sought to make himself master of it.
The first siege of Nisibis by Sapor lasted, we are told, sixty-three days. Few particulars of it have come down to us. Sapor had attacked the city, apparently, in the absence of Constantius, who had been called off to Pannonia to hold a conference with his brothers. It was defended, not only by its garrison and inhabitants, but by the prayers and exhortations of its bishop, St. James, who, if he did not work miracles for the deliverance of his countrymen, at any rate sustained and animated their resistance. The result was that the bands of Sapor were repelled with loss, and he was forced, after wasting two months before the walls, to raise the siege and own himself baffled.
After this, for some years the Persian war with Rome languished. It is difficult to extract from the brief statements of epitomizers, and the loose invectives or panegyrics of orators, the real circumstances of the struggle; but apparently the general condition of things was this. The Persians were constantly victorious in the open field; Constantius was again and again defeated; but no permanent gain was effected by these successes. A weakness inherited by the Persians from the Parthians—an inability to conduct sieges to a prosperous issue—showed itself; and their failures against the fortified posts which Rome had taken care to establish in the disputed regions were continual. Up to the close of A.D. 340 Sapor had made no important gain, had struck no decisive blow, but stood nearly in the same position which he had occupied at the commencement of the conflict.
But the year A.D. 341 saw a change. Sapor, after obtaining possession of the person of Tiranus, had sought to make himself master of Armenia, and had even attempted to set up one of his own relatives as king. But the indomitable spirit of the inhabitants, and their firm attachment to their Arsacid princes, caused his attempts to fail of any good result, and tended on the whole to throw Armenia into the arms of Rome. Sapor, after a while, became convinced of the folly of his proceedings, and resolved on the adoption of a wholly new policy. He would relinquish the idea of conquering, and would endeavor instead to conciliate the Armenians, in the hope of obtaining from their gratitude what he had been unable to extort from their fears. Tiranus was still living; and Sapor, we are told, offered to replace him upon the Armenian throne; but, as he had been blinded by his captors, and as Oriental notions did not allow a person thus mutilated to exercise royal power, Tiranus declined the offer made him, and suggested the substitution of his son, Arsaces, who was, like himself, a prisoner in Persia. Sapor readily consented; and the young prince, released from captivity, returned to his country, and was installed as king by the Persians, with the good-will of the natives, who were satisfied so long as they could feel that they had at their head a monarch of the ancient stock. The arrangement, of course, placed Armenia on the Persian side, and gave Sapor for many years a powerful ally in his struggle with Rome.
Thus Sapor had, by the, year A.D. 341, made a very considerable gain. He had placed a friendly sovereign on the Armenian throne, had bound him to his cause by oaths, and had thereby established his influence, not only over Armenia itself, but over the whole tract which lay between Armenia and the Caucasus. But he was far from content with these successes. It was still his great object to drive the Romans from Mesopotamia; and with that object in view it continued to be his first wish to obtain possession of Nisibis. Accordingly, having settled Armenian affairs to his liking, he made, in A.D. 346, a second attack on the great city of Northern Mesopotamia, again investing it with a large body of troops, and this time pressing the siege during the space of nearly three months. Again, however, the strength of the walls and the endurance of the garrison baffled him. Sapor was once more obliged to withdraw from, before the place, having suffered greater loss than those whom he had assailed, and forfeited much of the prestige which he had acquired by his many victories.
It was, perhaps, on account of the repulse from Nisibis, and in the hope of recovering his lost laurels, that Sapor, in the next year but one, A.D. 348, made an unusual effort. Calling out the entire military force of the empire, and augmenting it by large bodies of allies and mercenaries, the Persian king, towards the middle of summer, crossed the Tigris by three bridges, and with a numerous and well-appointed army invaded Central Mesopotamia, probably from Adiabene, or the region near and a little south of Nineveh. Constantius, with the Roman army, was posted on and about the Sinjax range of hills, in the vicinity of the town of Singara, which is represented by the modern village of Sinjar. The Roman emperor did not venture to dispute the passage of the river, or to meet his adversary in the broad plain which, intervenes between the Tigris and the mountain range, but clung to the skirts of the hills, and commanded his troops to remain wholly on the defensive. Sapor was thus enabled to choose his position, to establish a fortified camp at a convenient distance from the enemy, and to occupy the hills in its vicinity—some portion of the Sinjar range—with his archers. It is uncertain whether, in making these dispositions, he was merely providing for his own safety, or whether he was laying a trap into which he hoped to entice the Roman army. Perhaps his mind was wide enough to embrace both contingencies. At any rate, having thus established a point d'appui in his rear, he advanced boldly and challenged the legions to an encounter. The challenge was at once accepted, and the battle commenced about midday; but now the Persians, having just crossed swords with the enemy, almost immediately began to give ground, and retreating hastily drew their adversaries along, across the thirsty plain, to the vicinity of their fortified camp, where a strong body of horse and the flower of the Persian archers were posted. The horse charged, but the legionaries easily defeated them, and elated with their success burst into the camp, despite the warnings of their leader, who strove vainly to check their ardor and to induce them to put off the completion of their victory till the next day. A small detachment found within the ramparts was put to the sword; and the soldiers scattered themselves among the tents, some in quest of booty, others only anxious for some means of quenching their raging thirst. Meantime the sun had gone down, and the shades of night fell rapidly. Regarding the battle as over, and the victory as assured, the Romans gave themselves up to sleep or feasting. But now Sapor saw his opportunity—the opportunity for which he had perhaps planned and waited. His light troops on the adjacent hills commanded the camp, and, advancing on every side, surrounded it. They were fresh and eager for the fray; they fought in the security afforded by the darkness; while the fires of the camp showed them their enemies, worn out with fatigue, sleepy, or drunken. The result, as might have been expected, was a terrible carnage. The Persians overwhelmed the legionaries with showers of darts and arrows; flight, under the circumstances, was impossible; and the Roman soldiers mostly perished where they stood. They took, however, ere they died, an atrocious revenge. Sapor's son had been made prisoner in the course of the day; in their desperation the legionaries turned their fury against this innocent youth; they beat him with whips, wounded him with the points of their weapons, and finally rushed upon him and killed him with a hundred blows.
The battle of Singara, though thus disastrous to the Romans, had not any great effect in determining the course or issue of the war. Sapor did not take advantage of his victory to attack the rest of the Roman forces in Mesopotamia, or even to attempt the siege of any large town. Perhaps he had really suffered large losses in the earlier part of the day; perhaps he was too much affected by the miserable death of his son to care, till time had dulled the edge of his grief, for military glory. At any rate, we hear of his undertaking no further enterprise till the second year after the battle, A.D. 350, when he made his third and most desperate attempt to capture Nisibis.
The rise of a civil war in the West, and the departure of Constantius for Europe with the flower of his troops early in the year no doubt encouraged the Persian monarch to make one more effort against the place which had twice repulsed him with ignominy. He collected a numerous native army, and strengthened it by the addition of a body of Indian allies, who brought a large troop of elephants into the field. With this force he crossed the Tigris in the early summer, and, after taking several fortified posts, march northwards and invested Nisibis. The Roman commander in the place was the Count Lucilianus, afterwards the father-in-law of Jovian, a man of resource and determination. He is said to have taken the best advantage of every favorable turn of fortune in the course of the siege, and to have prolonged the resistance by various subtle stratagems. But the real animating spirit of the defence was once more the bishop, St. James, who raised the enthusiasm of the inhabitants to the highest pitch by his exhortations, guided them by his counsels, and was thought to work miracles for them by his prayers. Sapor tried at first the ordinary methods of attack; he battered the walls with his rams, and sapped them with mines. But finding that by these means he made no satisfactory progress, he had recourse shortly to wholly novel proceedings. The river Mygdonius (now the Jerujer), swollen by the melting of the snows in the Mons Masius, had overflowed its banks and covered with an inundation the plain in which Nisibis stands. Sapor saw that the forces of nature might be employed to advance his ends, and so embanked the lower part of the plain that the water could not run off, but formed a deep lake round the town, gradually creeping up the walls till it had almost reached the battlements. Having thus created an artificial sea, the energetic monarch rapidly collected, or constructed, a fleet of vessels, and, placing his military engines on board, launched the ships upon the waters, and so attacked the walls of the city at great advantage. But the defenders resisted stoutly, setting the engines on fire with torches, and either lifting the ships from the water by means of cranes, or else shattering them with the huge stones which they could discharge from their balistics. Still, therefore, no impression was made; but at last an unforeseen circumstance brought the besieged into the greatest peril, and almost gave Nisibis into the enemy's hands. The inundation, confined by the mounds of the Persians, which prevented it from running off, pressed with continually increasing force against the defences of the city, till at last the wall, in one part, proved too weak to withstand the tremendous weight which bore upon it, and gave way suddenly for the space of a hundred and fifty feet. What further damage was done to the town we know not; but a breach was opened through which the Persians at once made ready to pour into the place, regarding it as impossible that so huge a gap should be either repaired or effectually defended. Sapor took up his position on an artificial eminence, while his troops rushed to the assault. First of all marched the heavy cavalry, accompanied by the horse-archers; next came the elephants, bearing iron towers upon their backs, and in each tower a number of bowmen; intermixed with the elephants were a certain amount of heavy-armed foot. It was a strange column with which to attack a breach; and its composition does not say much for Persian siege tactics, which were always poor and ineffective, and which now, as usually, resulted in failure. The horses became quickly entangled in the ooze and mud which the waters had left behind them as they subsided; the elephants were even less able to overcome these difficulties, and as soon as they received a wound sank down—never to rise again—in the swamp. Sapor hastily gave orders for the assailing column to retreat and seek the friendly shelter of the Persian camp, while he essayed to maintain his advantage in a different way. His light archers were ordered to the front, and, being formed into divisions which were to act as reliefs, received orders to prevent the restoration of the ruined wall by directing an incessant storm of arrows into the gap made by the waters. But the firmness and activity of the garrison and inhabitants defeated this well-imagined proceeding. While the heavy-armed troops stood in the gap receiving the flights of arrows and defending themselves as they best could, the unarmed multitude raised a new wall in their rear, which, by the morning of the next day, was six feet in height. This last proof of his enemies' resolution and resource seems to have finally convinced Sapor of the hopelessness of his enterprise. Though he still continued the siege for a while, he made no other grand attack, and at length drew off his forces, having lost twenty thousand men before the walls, and wasted a hundred days, or more than three months.
Perhaps he would not have departed so soon, but would have turned the siege into a blockade, and endeavored to starve the garrison into submission, had not alarming tidings reached him from his north-eastern frontier. Then, as now, the low flat sandy region east of the Caspian was in the possession of nomadic hordes, whose whole life was spent in war and plunder. The Oxus might be nominally the boundary of the empire in this quarter; but the nomads were really dominant over the entire desert to the foot of the Hyrcanian and Parthian hills. Petty plundering forays into the fertile region south and east of the desert were no doubt constant, and were not greatly regarded; but from time to time some tribe or chieftain bolder than the rest made a deeper inroad and a more sustained attack than usual, spreading consternation around, and terrifying the court for its safety. Such an attack seems to have occurred towards the autumn of A.D. 350. The invading horde is said to have consisted of Massagatae; but we can hardly be mistaken in regarding them as, in the main, of Tatar, or Turkoman blood, akin to the Usbegs and other Turanian tribes which still inhabit the sandy steppe. Sapor considered the crisis such as to require his own presence; and thus, while civil war summoned one of the two rivals from Mesopotamia to the far West, where he had to contend with the self-styled emperors, Magnentius and Vetranio, the other was called away to the extreme East to repel a Tatar invasion. A tacit truce was thus established between the great belligerents—a truce which lasted for seven or eight years. The unfortunate Mesopotamians, harassed by constant war for above twenty years, had now a breathing-space during which to recover from the ruin and desolation that had overwhelmed them. Rome and Persia for a time suspended their conflict. Rivalry, indeed, did not cease; but it was transferred from the battlefield to the cabinet, and the Roman emperor sought and found in diplomatic triumphs a compensation for the ill-success which had attended his efforts in the field.