Surnamed the Younger, second son of Darius II.; conspired against his brother Artaxerxes Mnemon, was sentenced to death, pardoned, and restored to his satrapy in Asia Minor; conspired anew, raised a large army, including Greek mercenaries, marched against his brother, and was slain at Cunaxa, of which last enterprise and its fate an account is given in the "Anabasis" of Xenophon; d. 401 B.C.