Mithridates had been allowed to pursue his career of conquest unopposed, so far as the Syrians were concerned, and to establish his sway from the Hindoo Koosh to the Euphrates.

But a time at last came when home dangers were less pressing, and a prospect of engaging the terrible Parthians with success seemed to present itself.

The second Demetrius had not, indeed, wholly overcome his domestic enemy, Tryphon; but he had so far brought him into difficulties as to believe that he might safely be left to be dealt with by his wife, Cleopatra, and by his captains.

At the same time the condition of affairs in the East seemed to invite his interference, Mithridates ruled his new conquests with some strictness, suspecting, probably, their fidelity, and determined that he would not by any remissness allow them to escape from his grasp.

The native inhabitants could scarcely be much attached to the Syro-Macedonians, who had certainly not treated them very tenderly; but a possession of 170 years' duration confers prestige in the East, and a strange yoke may have galled more than one to whose pressure they had become accustomed.
Moreover, all the provinces which Parthia took from Syria contained Greek towns, and their inhabitants might at all times be depended on to side with their countrymen against the Asiatics.