Parthia

Parthia, ancient country of Asia, southeast of the Caspian Sea. The Parthian empire was established in 250 B.C., following a revolt, led by Arsace, against the Syrian empire. The Parthian empire reached its zenith under Mithradates I (171–138 B.C.) and II (123–88 B.C.). The Parthians conquered Persia and nearby lands, and their mounted archers successfully withstood Roman attacks until 38 B.C. In A.D. 226 the territory that had been under Parthian rule was taken over by Ardashir I, the founder of the Sassanid dynasty of Persia.