Nineteen months after Japanese forces attacked Pearl Harbor and forced the United States to enter World War II, boats carrying the 7th US Army landed on the shores of southern Sicily. Dubbed Operation Husky, the campaign to establish an Allied foothold in Sicily was led by two of the most noted American tacticians of the twentieth century: Major General George S. Patton Jr. and Major General Geoffrey Keyes. While Patton is the renowned subject of numerous books and films, Keyes's life and achievements have gone unrecognized, but his anonymity is by no means an accurate reflection of the value of his contributions and dedicated service in World War II and the Cold War. Patton's Tactician: The War Diary of Lieutenant General Geoffrey Keyes is the first transcribed edition of Keyes's personal diary to be published. Edited by James W. Holsinger Jr., the diary begins in October 1942, prior to the invasion of French Morocco and Keyes's engagement in World War II and the Cold War. Holsinger has integrated a variety of related sources, including correspondence between Keyes, Patton, and Eisenhower. A day-to-day chronicle of Keyes's experiences in the World War II Mediterranean theater and the early days of the Cold War in occupied Germany and Austria, Patton's Tactician is an invaluable primary source that offers readers a glimpse into the mind of one of America's most distinguished World War II corps commanders.