Answer
The answer is one year. In September 1939, World War II began. Admiral Günther Lütjens took command of the Bismarck in September 1940, one year later. Lütjens was an experienced naval commander and had served in the German Navy since 1902. He commanded the Bismarck during its only combat mission, which ended in the ship being sunk by the Royal Navy in May 1941.