Offended by the refusal of Julian to continue their subsidies, they had transferred their services wholly to the other side, and pursued the Romans with a hostility that was sharpened by indignation and resentment.

It was with difficulty that the Roman army, at the close of the fourth day, reached Dura, a small place upon the Tigris, about eighteen miles north of Samarah.

Here a new idea seized the soldiers.

As the Persian forces were massed chiefly on the left bank of the Tigris, and might find it difficult to transfer themselves to the other side, it seemed to the legionaries that they would escape half their difficulties if they could themselves cross the river, and place it between them and their foes.

They had also a notion that on the west side of the stream the Roman frontier was not far distent, but might be reached by forced marches in a few days.