Cambyses (kămbī´sēz), two kings of the Achaemenid dynasty of Persia. Cambyses I was king (c.600 BC) of Ansham, ruling as a vassal of Media. According to Herodotus he married the daughter of the Median king Astyages; some scholars dispute this. Cambyses' son was Cyrus the Great. Cambyses II, d. 521 BC, was the son and successor of Cyrus the Great and ruled as king of ancient Persia (529–521 BC). He disposed of his brother Smerdis in order to gain unchallenged rule. He invaded Egypt, defeating (525 BC) Psamtik at Pelusium and sacking Memphis. His further plans of conquest in Africa were frustrated, and at home an impostor claiming to be Smerdis raised a revolt. Cambyses died, possibly by suicide, when he was putting down the insurrection. Darius I succeeded him.