Nothing authentic has come down to us respecting Sapor during his father's lifetime; but from the moment that he mounted the throne, we find him engaged in a series of wars, which show him to have been of a most active and energetic character.

Armenia, which Artaxerxes had subjected, attempted (it would seem) to regain its independence at the commencement of the new reign; but Sapor easily crushed the nascent insurrection, and the Armenians made no further effort to free themselves till several years after his death.
Contemporaneously with this revolt in the mountain region of the north, a danger showed itself in the plain country of the south, where Manizen, king of Hatra, or El Hadhr, not only declared himself independent, but assumed dominion over the entire tract between the Euphrates and the Tigris, the Jezireh of the Arabian geographers.

The strength of Hatra was great, as had been proved by Trajan and Severus; its thick walls and valiant inhabitants would probably have defied every attempt of the Persian prince to make himself master of it by force.

He therefore condescended to stratagem.

Manizen had a daughter who cherished ambitious views.