Cyrus had, it is probable, little difficulty in obtaining their submission.

It is possible that they resisted; but perhaps it is more probable that their course on this occasion was similar to that which they pursued when the Macedonian conqueror swept across these same regions.

The Parthians at that period submitted without striking a blow.

There is no reason to believe that they caused any greater trouble to Cyrus.
When the Persian empire was organized by Darius Hystaspis into satrapies, Parthia was at first united in the same government with Chorasmia, Sogdiana, and Aria.

Subsequently, however, when satrapies were made more numerous, it was detached from these extensive countries and made to form a distinct government, with the mere addition of the comparatively small district of Hyrcania.40 It formed, apparently, one of the most tractable and submissive of the Persian provinces.