This book is a concise, readable introduction to the Greek author Thucydides, who is widely regarded as one of the foremost historians of all time. Why does Thucydides continue to matter today? Perez Zagorin answers this question by examining Thucydides' landmark work 'History of the Peloponnesian War', one of the great classics of Western civilisation. This history, Zagorin explains, is far more than a chronicle of conflict between Athens and Sparta, the two Greek superpowers in the 5th century BC. It is also a remarkable story of politics, decision-making, the uses of power, and the human and communal experiences of war. The author maintains that the work remains of permanent interest because of the exceptional intellect that Thucydides brought to the writing of history, and of the originality, penetration, and the breadth and intensity of vision that inform his narrative. The first half of the book discusses the intellectual and historical background to Thucydides' work and its method, structure, and view of the causes of the war. The following chapters deal with the portrayal of the Athenian leader Pericles and the account of some of the main episodes of the war, such as the revolution in Corcyra and the Athenian invasion of Sicily. The book concludes with an insightful discussion of Thucydides as a thinker and philosophic historian.