Cyrus, surnamed the Great, or the Elder, the founder of the Persian empire; began his conquests by overthrowing his grandfather Astyages, king of the Medes; subdued Croesus, king of Lydia; laid siege to Babylon and took it, and finished by being master of all Western Asia; was a prince of great energy and generosity, and left the nations he subjected and rendered tributary free in the observances of their religions and the maintenance of their institutions; this is the story of the historians, but it has since been considerably modified by study of the ancient monuments (560-529 B.C.).

Cyrus, 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.