The Ionian Alliance

Plato (428/427 BC ­ 348/347 BC), whose original name was Aristocles, was an ancient Greek philosopher, the second of the great trio of ancient Greeks, succeeding Socrates and preceding Aristotle­ who between them laid the philosophical foundations of Western culture. Plato was also a mathematician, writer of philosophical dialogues, and founder of the Academy in Athens, the first institution of higher learning in the western world. Plato is widely believed to have been a student of Socrates and to have been deeply influenced by his teacher's unjust death.
Plato's brilliance as a writer and thinker can be witnessed by reading his Socratic dialogues. Some of the dialogues, letters, and other works that are ascribed to him are considered spurious. Plato is thought to have lectured at the Academy, although the pedagogical function of his dialogues, if any, is not known with certainty. They have historically been used to teach philosophy, logic, rhetoric, mathematics, and other subjects about which he wrote.
Plato influenced the work of Aristotle, Neoplatonism, Cicero, Plutarch, Stoicism, Anselm, Descartes, Hobbes, Leibniz, Mill, Schopenhauer, Nietzsche, Heidegger, Arendt, Gadamer and countless other western philosophers and theologians. Plato's influences were Socrates, Homer, Hesiod, Aristophanes, Aesop, Protagoras, Parmenides, Pythagoras, Heraclitus and Orphism.
Plato's main interests were Rhetoric, Art, Literature, Epistemology, Justice, Virtue, Politics, Education, Family and Militarism

Plato was born to an aristocratic family in Athens. His father, Ariston, was believed to have descended from the early kings of Athens. Perictione, his mother, was distantly related to the 6th-century B.C. lawmaker Solon.
When Plato was a child, his father died, and his mother married Pyrilampes, who was an associate of the statesman Pericles. Plato's original name was Aristocles, but in his school days he received the nickname Platon (meaning "broad" ) because of his broad shoulders. It was mostly in Pyrilampes' house that Plato was brought up. Aristotle writes that when Plato was a young man he studied under Cratylus who was a student of Heracleitus, famed for his cosmology which is based on fire being the basic material of the universe. It almost certain that Plato became friends with Socrates when he was young, for Plato's mother's brother Charmides was a close friend of Socrates.

The Peloponnesian War was fought between Athens and Sparta between 431 BC and 404 BC. Plato was in military service from 409 BC to 404 BC but at this time he wanted a political career rather than a military one. At the end of the war he joined the oligarchy of the Thirty Tyrants in Athens set up in 404 BC, one of whose leaders being his mother's brother Charmides, but their violent acts meant that Plato quickly left.
In 403 BC there was a restoration of democracy at Athens and Plato had great hopes that he would be able to enter politics again. However, the excesses of Athenian political life seem to have persuaded him to give up political ambitions. In particular, the execution of Socrates in 399 BC had a profound effect on him and he decided that he would have nothing further to do with politics in Athens.

Plato left Athens after Socrates had been executed and traveled in Egypt, Sicily and Italy. In Egypt he learned of a water clock and later introduced it into Greece. In Italy he learned of the work of Pythagoras and came to appreciate the value of mathematics. He studied with the disciples of Pythagoras. Again there was a period of war and again Plato entered military service. It was claimed by later writers on Plato's life that he was decorated for bravery in battle during this period of his life. It is also thought that he began to write his dialogues at this time. On his return to Athens Plato founded, in about 387 BC, on land which had belonged to Academos, a school of learning which being situated in the grove of Academos was called the Academy. On his journeys he decided to devote the rest of his life to philosophy.

In 389 B.C. he founded a school in Athens. Because it was on the grounds that had once belonged to a legendary Greek called Academus, it came to be called the Academy, and this term has been used for schools ever since. The institution often described as the first European university. The Academy provided a comprehensive curriculum, including such subjects as astronomy, biology, mathematics, political theory, and philosophy. The main purpose of the Academy was to cultivate thought to lead to a restoration of decent government in the cities of Greece.
Only two further episodes in Plato's life are recorded.