The Oberkommando der Marine (OKM) was Nazi Germany's Naval High Command and the highest administrative and command authority of the Kriegsmarine. It was officially formed from the Marineleitung ("Naval Command") of the Reichswehr on 11 January 1936. In 1937 it was combined with the newly formed Seekriegsleitung (SKL). There were two major re-organisations, in November 1939 and May 1944. The Commanders-in-Chief (Oberbefehlshaber der Marine, or OBdM for short) of the Kriegsmarine were: