The Palmyrene prince was bent on taking advantage of the general confusion of the times to carve out for himself a considerable kingdom, of which Palmyra should be the capital.

Syria and Palestine on the one hand, Mesopotamia on the other, were the provinces that lay most conveniently near to him, and that he especially coveted.

But Mesopotamia had remained in the possession of the Persians as the prize of their victory over Valerian, and could only be obtained by wresting it from the hands into which it had fallen.
Odenathus did not shrink from this contest.

It had been with some reason conjectured that Sapor must have been at this time occupied with troubles which had broken out on the eastern side of his empire.

At any rate, it appears that Odenathus, after a short contest with Macriarius and his son, Quietus, turned his arms once more, about A.D.263, against the Persians, crossed the Euphrates into Mesopotamia, took Oarrhee and Nisibis, defeated Sapor and some of his sons in a battle, and drove the entire Persian host in confusion to the gates of Ctesiphon.