The Battle of Cunaxa is fought in 401 BCE between Cyrus the Younger and his elder brother Arsaces, who had seized the Persian throne as Artaxerxes II in 404 BCE.

The great battle of the revolt of Cyrus takes place 70 km north of Babylon, at Cunaxa, on the left bank of the Euphrates River.

The main source is a Greek eyewitness and soldier, Xenophon.