Astyages (ăstī´əjēz), fl. 6th cent. BC, king of the Medes (584–c.550 BC), son and successor of Cyaxares. His rule was harsh, and he was unpopular. His daughter is alleged to have married the elder Cambyses and was said to be the mother of Cyrus the Great, who rebelled against Astyages and overthrew him (c.550 BC), thus creating the Persian Empire.