Xenophon of Athens (c. 430 – 354/355 BCE) was a Greek military leader, philosopher, and historian. At the age of 30, he became one of the leaders of the Greek mercenaries known as the Ten Thousand, who participated in Cyrus the Younger's campaign to seize the Achaemenid Empire. His military experiences and writings have been influential in both historical and military studies.Xenophon was born in the deme of Erchia in Athens to an aristocratic family. He lived through the Peloponnesian War and was a contemporary of Plato. He associated with Socrates and likely served in the Athenian cavalry. He remained in Athens during the rule of the Thirty Tyrants and fought against democratic insurgents during the civil war of 403–404 BCE. His writings suggest he witnessed significant political events, including the return of Alcibiades and the trial of the generals.Invited by Proxenus of Beotia, a captain in Cyrus's army, Xenophon joined the expedition against Tissaphernes, the Persian satrap of Ionia. His memoir, Anabasis, recounts the journey of the Ten Thousand after Cyrus's death at the Battle of Cunaxa in 401 BCE. Following Cyrus's death, the mercenaries elected new leaders, including Xenophon, to guide them back to Greece. He demonstrated innovative military strategies during their retreat, including the use of feints and the establishment of reserves.The Ten Thousand faced numerous challenges, including hostile tribes and harsh weather conditions. Xenophon led them through various conflicts, employing tactical maneuvers to overcome obstacles. They eventually reached Trapezus on the Black Sea coast, where they allied with local forces and fought against the Colchians before returning to Greek territory.Xenophon's Anabasis concludes in 399 BCE with the arrival of the Spartan commander Thimbron. He later participated in campaigns under Dercylidas and Agesilaus II, the Spartan king, during the struggle for Ionian independence. Xenophon was banished from Athens for his alignment with Sparta and settled in Scillus, where he lived for many years until his death around 354 BCE.Xenophon also contributed to political philosophy through works such as Cyropaedia, which presents a fictionalized account of Cyrus the Great and explores themes of leadership and governance. His writings on Spartan society, including the Constitution of the Lacedaemonians, provide valuable insights into the political structures of ancient Greece. His Socratic dialogues, including the Apology and Memorabilia, serve as defenses of Socrates and reflect his philosophical interests.Xenophon's legacy endures through his historical accounts and philosophical inquiries, influencing both military thought and the study of leadership in subsequent generations.