In the summer of 1914 Europe exploded into a frenzy of mass violence. The war that followed had global repercussions, destroying four empires and costing millions of lives. Even the victorious countries were scarred for a generation, and we still today remain within the conflict's shadow. In this major new analysis, published ninety years after the First World War began, David Stevenson re-examines the causes, course, and impact of this 'war to end war', placing it in the context of its era and exposing its underlying dynamics. His book provides a wide-ranging international history, drawing on insights from the latest research. It offers compelling answers to the key questions about how this terrible struggle unfolded: questions that remain disturbingly relevant for our own time.