Arsacid prince of the Parthian Empire who revolted against King Phraates IV and drove him into exile (32 BC) among the Scythians. The next year Phraates returned, and Tiridates fled to Syria, taking Phraates' son as hostage. The Roman emperor Augustus returned the son, but not Tiridates, to Phraates. In the spring of 26, Tiridates launched an unsuccessful invasion of Mesopotamia, and he may have returned to Mesopotamia early in 25. Augustus, preoccupied with Spanish affairs, had no more use for Tiridates. By May of 25, Phraates seems to have regained power.