The reign of Phraates I.in Parthia coincides with that of Seleucus IV.

(Philopator) in Syria; and we may account for the inactivity of this prince, in part by his personal character, which was weak and pacific, in part by the exhaustion of Syria at the time, in consequence of his father's great war with Rome (B.C.

197-190), and of the heavy contribution which was imposed upon him at the close of it.

Syria may scarcely have yet recovered sufficient strength to enter upon a new struggle, especially one with a distant and powerful enemy.

The material interests of the Empire may also have seemed to be but little touched by the war, since the Mardi were too poor to furnish much tribute; and it is possible, if not even probable, that their subjection to Syria had long been rather formal than real.