General Jacob L. "Jake" Devers (1897--1979) was one of only two officers -- the other was Omar C. Bradley -- to command an army group during the decisive campaigns of 1944--1945 that liberated Europe and ended the war with Nazi Germany. After the war, Devers led the Army Ground Forces in the United States and eventually retired in 1949 after forty years of service. Despite incredible successes on the battlefield, General George C. Marshall's "dependable man" remains one of the most underrated and overlooked figures of his generation. In this definitive biography, James Scott Wheeler delivers a groundbreaking reassessment of the American commander whose contributions to victory in Europe are topped only by General Dwight D. Eisenhower's. Wheeler's exhaustively researched chronicle of Devers's life and career reveals a leader who demonstrated an extraordinary ability to cut through red tape and solve complex problems. Nevertheless, Eisenhower disliked Devers -- a fact laid bare when he ordered Devers's Sixth Army Group to halt at the Rhine. After the war, Eisenhower's and Bradley's accounts of the generals' disagreements over strategy and tactics became received wisdom, to the detriment of Devers's reputation. An essential contribution to twentieth-century history, Jacob L. Devers provides a fresh and nuanced interpretation of the senior command during World War II and offers a new perspective on a highly accomplished soldier.