The Peloponnesian War lasted for twenty-seven years, from 431-404 BC, and in Greek history holds a comparable place to that of the First World War in Europe. It was a power struggle in which Athens and her allies were finally conquered by the confederation led by Sparta, as the Central Powers were defeated by the Allies in the 1914-1918 War. The Peloponnesian War is a vital part of military history due to the enormous changes that occurred as a result of the conflict and, more specifically, as it displays the importance of having clear politico-strategic objectives, the interplay of maritime and land operations, and the problems of achieving cohesion in an alliance when all the participants see themselves as fellow citizens. In this brilliant new book, Sir Nigel Bagnall sets out to analyse and clarify the war, describing in compelling detail the events that led up to it. He highlights the complex inter-relationship between the Greek states, and closely studies the politico-strategic conduct of the two principal contestants. His refreshing stance differs from the traditional accounts of the conflict due to the vast amount of attention he gives to the historical context of the war.