Which Achaemenid prince led the Persian army defeated at the Battle of Cunaxa in 401 BCE?

Cyrus the Younger led the Persian army defeated at the Battle of Cunaxa in 401 BCE.

Cyrus the Younger was a son of Darius II and a younger brother of King Artaxerxes II. He recruited Greek mercenaries, including the force later known as the Ten Thousand, to support his attempt to seize the Persian throne.

At Cunaxa, near Babylon, Cyrus’s troops initially performed well, but Cyrus charged toward his brother and was killed. His death ended the rebellion even though some of his soldiers had won their part of the battlefield. The Greek mercenaries were left deep inside the Persian Empire without their employer.

Their difficult journey home was described by Xenophon in the Anabasis. The episode offers an unusually detailed Greek account of Persian politics, military organization, and geography, but it reflects the perspective of a participant in the retreat.