Vimy Ridge was one of the most important geographic features on the entire Western Front in World War I. In early 1917 it was considered practically impregnable, but on 9 April the Canadian Army Corps, under the command of the British Lieutenant General Sir Julian Byng, assaulted it as part of the Arras offensive. In one of the most spectacular operational attacks of the war, they seized almost the entire ridge in a single day. This book describes how the innovative efforts that went into every aspect of the preparation for this attack ensured that the Canadian and British troops achieved unprecedented success.