Clearchus (c. 450–401 BC)

Spartan general. After serving in the Peloponnesian War, he was appointed governor of Byzantium and successfully protected the city against Thracian attacks. He established himself as tyrant of Byzantium 403 and refused to obey when he was recalled by the ephors (the five principal Spartan magistrates). He was sentenced to death and took refuge with Cyrus the Younger, who was planning to overthrow his brother, the Persian king Artaxerxes II. He gathered a large force of Greek mercenaries and marched with Cyrus 401 BC. Cyrus was defeated and killed at Cunaxa, and Clearchus and other Greek generals were taken prisoner and executed.