 In July 1937, the "Oberbefehlshaber der Marine" (commander in chief of the navy) requested proposals from both the naval design staff as well as private dockyards.None of the designs by the dockyards were practical, and so the official design, which only met some of the requirements, was chosen.During further development of the design, serious flaws became apparent, including the weakness of both the main battery and anti-aircraft armament, as well as the insufficiently thick armor protection.