Clearchus or Clearch, the son of Rhamphias, was a Spartan general and mercenary, noted for leading the Ten Thousand in battle against the Persian king.
Clearchus of Sparta at the 401 BC Battle of Cunaxa, by Adrien Guignet.
The Ten Thousand were a force of mercenary units, mainly Greeks, employed by Cyrus the Younger to attempt to wrest the throne of the Persian Empire from his brother, Artaxerxes II. Their march to the Battle of Cunaxa and back to Greece was recorded by Xenophon, one of their leaders, in his work Anabasis.
Route of Xenophon and the Ten Thousand (red line) in the Achaemenid Empire. The satrapy of Cyrus the Younger is delineated in green.
Xenophon's Anabasis.
Retreat of the Ten Thousand at the Battle of Cunaxa, by Jean-Adrien Guignet. Louvre
Xenophon and the Ten Thousand hail the sea, 19th-century illustration