The hopes of the besieged lay, primarily, in their receiving relief from without by the advance of an army capable of engaging their assailants and harassing them or driving them off; secondarily, in successful sallies, by means of which they might destroy the enemy's works and induce him to retire from before the place.
There existed, in the neighborhood of Amida, the elements of a relieving army, under the command of the new prefect of the East, Sabinianus.
Had this officer possessed an energetic and enterprising character, he might, without much difficulty, have collected a force of light and active soldiers, which might have hung upon the rear of the Persians, intercepted their convoys, cut off their stragglers, and have even made an occasional dash upon their lines.

Such was the course of conduct recommended by Ursicinus, the second in command, whom Sabinianus had recently superseded; but the latter was jealous of his subordinate, and had orders from the Byzantine court to keep him unemployed.

He was himself old and rich, alike disinclined to and unfit for military enterprise; he therefore absolutely rejected the advice of Ursicinus, and determined on making no effort.

He had positive orders, he said, from the court to keep on the defensive and not endanger his troops by engaging them in hazardous adventures.

Amida must protect itself, or at any rate not look to him for succor.