The defence, however, proved stronger than the attack.

Time after time the bold sallies of the besieged destroyed the Roman works.

At last the rainy season set in, and the low ground outside the town became a glutinous and adhesive marsh.

It was no longer possible to continue the siege; and the disappointed emperor reluctantly drew off his troops, recrossed the Euphrates, and retired into winter quarters at Antioch.
The successes of Sapor in the campaigns of A.D.359 and 360, his captures of Amida, Singara, and Bezabde, together with the unfortunate issue of the expedition made by Constantius against the last-named place, had a tendency to shake the fidelity of the Roman vassal-kings, Arsaces of Armenia, and Meribanes of Iberia.

Constantius, therefore, during the winter of A.D.