Just as Greece was quieted by the end of the Peloponnesian war, the old King of Persia, Darius Nothus, died, and his eldest son, Artaxerxes Mnemon, came to the throne.  He was the eldest, but his brother Cyrus, who had been born after his father began to reign, declared that this gave the best right, and resolved to march from Sardis into Persia to gain the kingdom for himself by the help of a hired body of Greek soldiers.  Clearchus, a banished Spartan, undertook to get them together, and he made such descriptions of the wealth they would get in the East, that 11,000 of the bravest men in Greece came together for the purpose, and among them Xenophon, the pupil of Socrates, who has written the history of the expedition, as well as that of the later years of the Peloponnesian war.  Xenophon was a horseman, but most of the troops were foot soldiers, and they were joined by a great body of Asiatics, raised by Cyrus himself.  They were 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 Greeks beat all who met them; but in the meantime Cyrus was killed, and his whole army broke up and fled, so that the Greeks were left to themselves in the enemy’s country, without provisions, money, or guides.