It was within twenty years of this unfortunate attempt that the dominion of the Seleucidae over Persia and the adjacent countries came to an end. The Parthian Empire had for nearly a century been gradually growing in power and extending itself at the expense of the Syro-Macedonian; and, about B.C. 163, an energetic prince, Mithridates I., commenced a series of conquests towards the West, which terminated (about B.C. 150) in the transference from the Syro-Macedonian to the Parthian rule of Media Magna, Susiana, Persia, Babylonia, and Assyria Proper. It would seem that the Persians offered no resistance to the progress of the new conqueror. The Seleucidae had not tried to conciliate their attachment, and it was impossible that they should dislike the rupture of ties which had only galled hitherto. Perhaps their feeling, in prospect of the change, was one of simple indifference. Perhaps it was not without some stir of satisfaction and complacency that they saw the pride of the hated Europeans abased, and a race, which, however much it might differ from their own, was at least Asiatic, installed in power. The Parthia system, moreover, was one which allowed greater liberty to the subject races than the Macedonian, as it had been understood and carried out by the Seleucidae; and so far some real gain was to be expected from the change. Religious motives must also have conspired to make the Persians sympathize with the new power, rather than with that which for centuries had despised their faith and had recently insulted it. The treatment of the Persians by their Parthian lords seems, on the whole, to have been marked by moderation. Mithridates indeed, the original conqueror, is accused of having alienated his new subjects by the harshness of his rule; and in the struggle which occurred between him and the Seleucid king, Demetrius II., Persians, as well as Elymseans and Bactrians, are said to have fought on the side of the Syro-Macedonian. But this is the only occasion in Parthian history, between the submission of Persia and the great revolt under Artaxerxes, where there is any appearance of the Persians regarding their masters with hostile feelings. In general they show themselves submissive and contented with their position, which was certainly, on the whole, a less irksome one than they had occupied under the Seleucidae.