The Battle of Cunaxa was fought in the late summer of 401 BC between the Persian king Artaxerxes II and his brother Cyrus the Younger for control of the Achaemenid throne.

The great battle of the revolt of Cyrus took place 70 km north of Babylon, at Cunaxa (Greek: Κούναξα), on the left bank of the Euphrates.

Cyrus gathered an army of Greek mercenaries, consisting of 10,400 hoplites and 2,500 light infantry and peltasts, under the Spartan general Clearchus, and met Artaxerxes at Cunaxa.

[5] Cyrus then approached Clearchus, the leader of the Greeks, who was commanding the phalanx stationed on the right, and ordered him to move into the center so as to go after Artaxerxes.

Clearchus refused this owing to the insecurity that the Greeks had for their right flank, which tended to drift and was undefended, as the shields were held in the left hand.

That Clearchus did not obey this order is a sign of the lack of control that Cyrus had over his army, as a couple of other occasions throughout this campaign prior to the battle reveal also.

Before the final attack began, Xenophon, the main relater of the events at Cunaxa, who was probably at the time some kind of mid-level officer, approached Cyrus to ensure that all the proper orders and dispositions had been made.

[5] The Greeks, deployed on Cyrus's right and outnumbered, charged the left flank of Artaxerxes' army, which broke ranks and fled before they came within arrowshot.

[8] Ctesias was the author of treatises on rivers, and on the Persian revenues, of an account of India entitled Indica (Ἰνδικά), and of a history of Assyria and Persia in 23 books, called Persica (Περσικά), written in opposition to Herodotus in the Ionic dialect, and professedly founded on the Persian Royal Archives.