Clearcihs, a Lacedaemonian general, distinguished in the last years of the Peloponnesian war, and at its close sent to Thrace to protect the Greeks against the barbarians. Recalled by the ephors, he refused to obey, and was sentenced to death. He then went over to Cyrus the Younger, governor of Lydia and other provinces of Asia Minor, and followed him (401 B. C.) as commander of 13,000 enlisted Greek mercenaries, on his expedition against his brother Artaxerxes II. None of his followers knew the secret aim of their long marches from province to province until they reached the plains of Babylonia, and the skill of Clearchns in leading them was as admirable as his valor. At the battle of Cunaxa Clearchns commanded the right wing of the Grecian army; and after the death of Cyrus, when the Greeks retreated fighting, he was tacitly recognized as their commander-in-chief, He and his chief officers having accepted the invitation of Tissaphernes, the Persian commander, to come to a friendly conference in his camp, they were seized, sent to the court of Artax-erxes, and put to death.

Left without commanders and in despair, the Greeks were saved by Xenophon, who admirably led their retreat, no less admirably described in his Anabasis.