Cunaxa

The fatal dart was thrown by Gryllus, son of Xenophon, the historian and leader of the ten thousand Greeks on their retreat from the battle-field of Cunaxa to the Black Sea.

This was after the battle of Cunaxa, where the younger Cyrus was defeated and slain.

They p. 182were marched across Syria, crossed the present river Euphrates at the ford Thapsacus, and at Cunaxa, seven miles from Babylon, they met the enormous army which Artaxerxes had raised. 

The battle of Cunaxa was fatal to Cyrus; he was slain and his camp was pillaged.

This is generally supposed to have been Cunaxa, where, according to Plutarch, the battle was fought.