Xenophon's dates make him an almost exact contemporary of Plato (429-347), and with Plato he is the major source of our information about their common master Socrates. Xenophon's unusual name, a compound of the Greek words for foreigner (xenos) and voice (phone), was no doubt intended to call attention to his family's foreign connections, a sure mark of aristocratic pedigree. By economic circumstance and military choice Xenophon belonged to one of the four Athenian property classes, the Hippeis (cavalrymen) class.
His most ancient biographer, Diogenes Laertius (fl. early third century B.C.E.) called Xenophon “modest and most superlatively handsome” and adds the story of his first encounter with Socrates, who allegedly blocked his passage in an alleyway and asked him where he might find various products. After Xenophon had answered several queries, Socrates asked him where men might become honorable and virtuous (kaloi kai agathoi). When Xenophon confessed his ignorance, Socrates replied, “Then follow me and learn.” “And from that time on, ” adds Diogenes Laertius, “Xenophon was Socrates' disciple” (Anabase I.16; cf. Anderson, 9).
Toward the end of the Peloponnesian War (404-403), Xenophon, then about twenty-five, served in the Athenian cavalry and was a member of Socrates' circle. He never hid his upper-class sympathies and was fundamentally hostile toward Athenian democracy. He probably supported the rule of the Thirty Oligarchs (404-403) and became unpopular in Athens after their defeat and the restoration of democracy. His unpopularity in Athens cannot be separated from his association with Socrates: several members of Socrates' circle were Oligarchs, and all were members of the upper classes and were held in suspicion by the Five Hundred, who ruled after 403.
Xenophon left Athens in 401 and enlisted as a Greek mercenary officer in