 He describes the Persian Cyrus as leading the campaign to conquer Babylon in 539 BC, while his uncle Cyaxares remained in Ecbatana.Cyaxares was by then an old man, and because Cyrus was in command of the campaign, the army came to regard Cyrus as king.After Cyrus invited Cyaxares to a palace he had prepared for him in Babylon, Cyaxares granted him his daughter (Cyrus’s first cousin) in marriage, with the Median kingdom as her dowry.