He recommended that the old plan of sitting down before walled towns should be given up, and that the Persian monarch, leaving the strongholds of Mesopotamia in his rear, should press forward to the Euphrates, pour his troops across it, and overrun the rich province of Syria, which he would find unguarded, and which had not been invaded by an enemy for nearly a century.

The views of Antoninus were adopted; but, in practice, they were overruled by the exigencies of the situation.

A Roman army occupied Mesopotamia, and advanced to the banks of the Tigris.

When the Persians in full force crossed the river, accompanied by Chionite and Albanian allies, they found a considerable body of troops prepared to resist them.

Their opponents did not, indeed offer battle, but they laid waste the country as the Persians took possession of it; they destroyed the forage, evacuated the indefensible towns (which fell, of course, into the enemy's hands), and fortified the line of the Euphrates with castles, military engines, and palisades.
Still the programme of Antoninus would probably have been carried out, had not the swell of the Euphrates exceeded the average, and rendered it impossible for the Persian troops to ford the river at the usual point of passage into Syria.