The First World War created the modern world. It was a conflict of unparalleled ferocity that extended far beyond its European epicentre and broke the century of relative peace and prosperity which we associate with the Victorian era. The First World War unleashed the demons of the 20th century - pestilence, military destruction and mass death - and also the ideas which continue to shape our world today - modernism in the arts, new approaches to psychology and medicine, and radical ideas about economics and society. An event of this scale and complexity needs a distinguished historian to portray it, and in this book, John Keegan fulfils a life-long ambition to write a full account of the war. The war was foremost a military conflict, and the battles on land, sea and in the air form the narrative heart of this study, with some fascinating new interpretations of the military events. The First World War also acted as a formidable engine for social change throughout the world, and this is brilliantly revealed in this book.