Plato, one of the greatest philosophers of all time, was born in Athens around 428 or 427 BC. It was a time of war and political upheaval, and that turmoil affected Plato's childhood and youth and certainly influenced his ideas. Plato's family members where heavily involved in Athenian politics, and he himself might have been a member of the Athenian cavalry.
Plato, however, did not choose either a political or a military career. Rather, led by his teacher, Socrates, he chose to become a philosopher and battled against the Sophists, a group of so-called philosophers who advocated relativism, rhetoric, and argument over truth. Plato made it his job to oppose them and their tendency toward corruption and anarchy.
Plato's early writings are largely dialogues, with Socrates as the star of the philosophical show. Works from this era include Apology, Protagoras, Gorgias, Crito, and Lysis, and Plato often does not draw a firm conclusion about the ideas expressed in them. He wants readers to form their own ideas and conclusions by thinking about what they read.
As the years passed, Plato spent much time traveling throughout the Mediterranean world. He even visited Egypt. When he returned to Athens, he founded the Academy as a refuge for thinkers and scholars to seek and discuss the nature of truth, life, and the world. Plato wrote works like Republic, Meno, Phaedo, and Symposium during the early years of the Academy, and in them, he focuses on government, morality, knowledge, and being. It is during this Middle Period that he discusses his Theory of Forms.
Later in Plato's life, he wrote works like Laws, Timaeus, Critias, and Statesmen in which he reexamines his earlier ideas and makes a more pragmatic shift. Plato died around the age of eighty after years of teaching in the Academy and writing. Thirty-five of his works and a few letters have come down to us.