With this force Cyrus set out from Sardis, in the spring of 401 B.C. He marched without opposition across Asia Minor and Mesopotamia to Babylonia, into the very heart of the Persian empire. Here, at Cunaxa, he was confronted by Artaxerxes with a force of more than half a million of men. The Barbarian allies of Cyrus were scattered at the first onset of the enemy; but the Greeks stood like a rampart of rock. Cyrus, however, was slain; and the other Greek generals, having been persuaded to enter into a council, were treacherously murdered by the Persians. The Greeks, in a hurried night meeting, chose new generals to lead them back to their homes. One of these was Xenophon, the popular historian of the expedition. Now commenced one of the most memorable retreats in all history. After a most harassing march over the hot plains of the Tigris and the icy passes of Armenia, the survivors reached the Black Sea, the abode of sister Greek colonies. THEBAN SUPREMACY (371-362 B.C.).--Throughout all the period of her supremacy, Sparta dealt selfishly and tyrannically with the other Grecian states. But at last the fiery resentment kindled by her oppressive measures inspired such a determined revolt against her as brought to an end her assumed supremacy over her sister cities. It was a city in Boeotia that led the uprising against Sparta. This was Thebes. The oligarchical government which the Lacedæmonians had set up in that capital was overthrown by Pelopidas at the head of the so-called Sacred Band, a company of three hundred select men who were bound by oath to stand by each other to the last. Pelopidas was seconded in all his efforts by Epaminondas, one of the ablest generals the Grecian race ever produced. Under the masterly guidance and inspiration of these patriot leaders, Thebes very soon secured a predominating influence in the affairs of Greece. It was Epaminondas who, when his enemies sought to disgrace and annoy him by electing him "public scavenger," made, in accepting the office, the memorable utterance, "If the office will not reflect honor upon me, I will reflect honor upon it." At Leuctra (371 B.C.) the Thebans earned the renown of being the most invincible soldiers in the world by completely overthrowing, with a force of six thousand men, the Spartan army of twice that number. This is said to have been the first time that the Spartans were ever fairly defeated in open battle. Their forces had been annihilated, as at Thermopylæ,--but annihilation is not defeat. From the victory of Leuctra dates the short but brilliant period of Theban supremacy. The year after that battle Epaminondas led an army into the Peloponnesus to aid the Arcadians, who had risen against Sparta. Laconia was ravaged, and for the first time Spartan women saw the smoke of fires kindled by an enemy.