Parthia, ancient empire of Asia, in what are now Iran and Afghanistan. The Parthians were of Scythian descent, and adopted median dress and aryan speech. They were excellent horsemen and archers. In battle, mounted Parthians often discharged their arrows back toward the enemy while pretending to flee; this is the origin of the phrase “a parthian shot.” Orodes I was probably the son of Mithradates II. His place in Parthian history is that of reuniting the empire by expelling Gotarzes from Babylonia, after he tried to take over.