Field Marshal Wilhelm Keitel was the head of the Oberkommando der Wehrmacht (OKW; Armed Forces High Command), making him one of the most powerful military figures in Nazi Germany. Admiral Karl Dönitz was the architect of Germany’s World War II submarine fleet, and he served as Hitler’s successor in the final days of the Third Reich. Although Gerd von Rundstedt was retired when war broke out in 1939, he returned to active service and was promoted to field marshal for his role in the conquest of France. Rundstedt would prove to be one of Hitler’s ablest commander on both fronts. Field Marshal Erich von Manstein was arguably the Wehrmacht’s most gifted commander, a fact that was recognized by the Western Allies after the war; in 1955 he was called upon to help establish the West German army.