It is not really surprising, though the historian of the war regards it as needing explanation, that no attempt was made to relieve Singara by the Romans. The siege was short; the place was considered strong; the nearest point held by a powerful Roman force was Nisibis, which was at least sixty miles distant from Singara. The neighborhood of Singara was, moreover, ill supplied with water; and a relieving army would probably have soon found itself in difficulties. Singara, on the verge of the desert, was always perilously situated. Rome valued it as an outpost from which her enemy might be watched, and which might advertise her of a sudden danger, but could not venture to undertake its defence in case of an attack in force, and was prepared to hear of its capture with equanimity.
From Singara Sapor directed his march almost due northwards, and, leaving Nisibis unassailed upon his left, proceeded to attack the strong fort known indifferently as Phoenica or Bezabde. This was a position on the east bank of the Tigris, near the point where that river quits the mountains and debouches upon the plain; though not on the site, it may be considered the representative of the modern Jezireh, which commands the passes from the low country into the Kurdish mountains. Bezabde was the chief city of the province, called after it Zabdicene, one of the five ceded by Narses and greatly coveted by his grandson. It was much valued by Rome, was fortified in places with a double wall, and was guarded by three legions and a large body of Kurdish archers. Sapor, having reconnoitred the place, and, with his usual hardihood, exposed himself to danger in doing so, sent a flag of truce to demand a surrender, joining with the messengers some prisoners of high rank taken at Singara, lest the enemy should open fire upon his envoys. The device was successful; but the garrison proved stanch, and determined on resisting to the last. Once more all the known resources of attack and defence were brought into play; and after a long siege, of which the most important incident was an attempt made by the bishop of the place to induce Sapor to withdraw, the wall was at last breached, the city taken, and its defenders indiscriminately massacred. Regarding the position as one of first-rate importance, Sapor, who had destroyed Singara, carefully repaired the defences of Bezabde, provisioned it abundantly, and garrisoned it with some of his best troops. He was well aware that the Romans would feel keenly the loss of so important a post, and expected that it would not be long before they made an effort to recover possession of it.