Anabasis, Book 1, Ch. 10 - Confusion at Cunaxa
The armies continued to grapple with each other, if Xenophon is to be believed, the Persians quite ran away when merely threatened by the Greeks.
While they were deliberating this, the King set up against the Greek battle line, re-orienting his army to the same formation as it had in fighting the first encounter. … He saw the Greeks close by and in battle formation, once again singing the paean, attacking more zealously than before. The Persians did not meet the attack, but even more than before, they ran away. The Greeks pursued them as far as a certain village, where they halted. Beyond the village was a hillock, where the King’s men made a stand - no infantry, just the cavalry occupied the hill, so that their arrangements could be seen. And they saw the King’s standard, said to be a golden eagle on a shield, held aloft on a pole. And when the Greeks came there, of course even the cavalry fled from the hill, until it was completely unoccupied. Clearchus did not go up on the hill, but stayed with the army, sending Lycius the Syracusan and another fellow up the hill, and ordered them to reconnoiter from the crest and report what they saw. So Lycius went up, looked around, and reported that they had fled quite hastily. And about that time the sun went down. The Greeks halted there and putting down their weapons, rested. They started to wonder that Cyrus hadn’t appeared anywhere and that none of his men were present, because they didn’t know he had been killed. But they guessed that he had gone off in pursuit or to occupy some other point.
The “certain village” was identified by other ancient sources as Cunaxa; Xenophon never names it. It is not far from Mahmoudiyah in modern Iraq.
The footnotes indicate that the “golden eagle” was almost certainly the so-called faravahar, a winged human, the symbol of the Persian King.
Anabasis - On the character of Clearchus
Anabasis, Book 1 - Review
Anabasis, Book 2, Ch. 1 - Ariaeus demurs
Anabasis, Book 2, Ch. 2 - Jitters and a Joke in the night
Anabasis - More on Clearchus