Meanwhile Sapor set the Arabs and Armenians in motion, inducing the Pagan party among the latter to rise in insurrection, deliver their king, Tiranus, into his power, and make incursions into the Roman territory, while the latter infested with their armed bands the provinces of Mesopotamia and Syria.

He himself was content, during the first year of the war, A.D.337, with moderate successes, and appeared to the Romans to avoid rather than seek a pitched battle.

Constantius was able, under these circumstances, not only to maintain his ground, but to gain certain advantages.

He restored the direction of affairs in Armenia to the Roman party, detached some of the Mesopotamian Arabs from the side of his adversary, and attached them to his own, and even built forts in the Persian territory on the further side of the Tigris.

But the gains made were slight; and in the ensuing year (A.D.