Cambyses killed his brother Bardiya in secret; a man ruled Persia under the dead brother's name until Darius killed him and took the throne

Cyrus the Great left two sons, Cambyses and Bardiya, whom the Greeks called Smerdis. Darius's Behistun inscription says Cambyses killed Bardiya and the people did not know it. Herodotus says Cambyses had a dream that Smerdis sat on the royal throne and sent his trusted man Prexaspes to kill him. While Cambyses was in Egypt, a man claimed the throne as Bardiya. Darius calls him Gaumata the Magian and says he rebelled on 11 March 522 BC and seized the kingdom on 1 July, and that Persia and Media went over to him. Cambyses died. Darius says Gaumata killed many who had known the real Bardiya, so no one would recognise the fraud. On 29 September 522 BC Darius and a few men killed him at a fortress in Media. Darius says he gave back the temples, pastures, herds and houses the impostor had taken. Herodotus says Darius then married Cyrus's daughters Atossa, who had been the wife of Cambyses and then of the impostor, and Artystone, and also Parmys, the daughter of the real Bardiya. Livius notes that Herodotus and the inscription disagree on when Bardiya was killed. Both accounts trace back to Darius's side, the side that won the throne. Darius carved his version in three languages on the cliff at Behistun, where it still stands.