Plato, mathematician, philosopher and founder of the Academy in Athens, is, together with his teacher, Socrates, and his student, Aristotle, universally considered to have laid the foundations of Western philosophy. His philosophical dialogues remain among the most widely read and influential of all philosophical texts and his enduring influence on virtually every area of philosophical enterprise cannot be exaggerated. This comprehensive and accessible guide to Plato's life and times includes more than 140 entries, written by a team of leading experts in the field of ancient philosophy, covering every aspect of Plato's thought. The Companion presents details of Plato's life, historical, philosophical and literary context, synopses of all the dialogues attributed to Plato, a comprehensive overview of the various features, themes and topics apparent in the dialogues, and a thorough account of his enduring influence and the various interpretative approaches applied to his thought throughout the history of philosophy. This is an essential reference tool for anyone working in the field of ancient philosophy.