Plato is one of history's most influential thinkers, the "sublime philosopher" whose writings remain foundational to Western culture. He is known for the brilliant dialogues in which he depicted his teacher, Socrates, discussing ethical truths with prominent citizens of Athens. Yet the image we have of Plato--an ethereal figure far removed from society and politics, who conjured abstract ideas in peaceful groves--is a fiction, created by Plato's admirers and built up over centuries. In fact, Plato was very much a man of the world.In Plato and the Tyrant, acclaimed historian and classicist James Romm draws on personal letters of Plato--documents that have long been kept in obscurity--to show how a philosopher helped topple the leading Greek power of the era: the opulent city of Syracuse. There, Plato encountered two authoritarian rulers, a father and son both named Dionysius, and tried to steer them toward philosophy. At the same time, he worked on his masterpiece, Republic, in which he conceived a ruler who unites perfect wisdom with absolute power. That dream has echoed down through the ages and given rise to a famous term, one that Plato himself didn't actually use: philosopher-king.As Romm reveals, Plato's time in Syracuse helped shape Republic--and also had disastrous results for Plato himself and for all of Greek Sicily. The younger Dionysius, emotionally unstable but intellectually curious, welcomed Plato with open arms, but soon the relationship soured. Plato's close friendship with Dionysius's uncle, Dion--possibly a bond of romantic love--created a rift in the ruling family that led to a chaotic civil war.Combining thrilling political drama with explorations of Plato's most cherished ideas, Romm takes us into the heart of Greece's late classical age, a time when many believed that democracy had failed. Plato's search for solutions led him to write his fervent plea for a new political order, and also led him to a place where he believed his theories might be put into practice. But Plato and the Tyrant demonstrates how Plato's experiment with enlightened autocracy spiraled into catastrophe, and also gives us nothing less than a new account of the origins of Western political thought.