Cyrus II was the brother of the Persian King, Artaxerxes II, and developed elaborate plans for seizing the throne himself. During the final years of the Peloponnesian War, he gave significant aid to Sparta, and when the war was over, gathered an army, which included 10,000, Greeks, mostly Spartans. His ostensible purpose was to lead an expedition to put down an unruly tribe in the Taurus mountains, but at the last minute, changed course and marched towards Babylon. Artaxeres II barely had warning to put together an army to meet Cyrus at Cuxana. During the battle Xenophon stated that the Greek heavy troops scattered their opposition twice; only one Greek was even wounded. Only after the battle did they hear that Cyrus had been killed, making their victory irrelevant and the expedition a failure.
The Greek army, under Clearchus the Spartan, was now left stranded thousands of miles inside enemy territory. At first Tissaphernes, a Satrap of Caris, offered to guide them back to Asia Minor, but after gaining their trust, treacherously killed their leaders, and surrounded the army. The Greeks, at this point, elected new officers and decided to fight their way out through the mountains of Asia Minor in order to avoid confronting an amassed Persian Army bent on their annihilation. Their retreat lasted over a year, and involved dozens of skirmishes with local tribes, near starvation, and forced marches through desolate mountains in the winter.
The entire expedition was recorded by Xenophon, a Athenian Scholar, an student of Socrates, who accompanied the group as an aide, but was elected an officer, after the murder of their original leaders. His work, The Anabasis, (the title means "The March Up"), is one of the classics of ancient literature.
http://en.wikipedia.org/wiki/Cunaxahttp://en.wikipedia.org/wiki/Ten_Thousand_(Greek)
