Res Gestae

Then, to bring about a feeling of security in the crisis and to encourage those who were submissive, he promoted Mamertinus, the pretorian prefect in Illyricum, to the consulship, as well as Nevitta; and that too although he had lately beyond measure blamed Constantine as the first to raise the rank of base foreigners.[*](See xxi. 10, 8.)

While by these and similar means Julian, wavering between hope and fear, was planning new measures, Constantius at Edessa, troubled by the varying reports of his scouts, was hesitating between two different courses, now preparing his soldiers for battle in the field, now, if opportunity should offer, planning a second siege of Bezabde, with the prudent design of not leaving the flank of Mesopotamia unprotected when he was presently about to march to the north.

But in this state of indecision he was kept back by many delays, since the Persian king was waiting on the other side of the Tigris until the signs from heaven should warrant a move; for if Sapor had crossed the river and found no one to oppose him, he could easily have penetrated to the Euphrates; besides this, since he was keeping his soldiers in condition for civil war, he feared to expose them to the dangers of an attack upon a walled city, knowing by experience the strength of its fortifications and the energy of its defenders.