In April 1940, during the invasion of Denmark and Norway (Operation Weserübung), he served as Vizeadmiral (vice admiral), commanding the distant cover forces in the North Sea—which consisted of Scharnhorst and Gneisenau. His superior, Vizeadmiral Wilhelm Marschall, had fallen ill just before the operation, so he assumed command of the Narvik and Trondheim landings.[23]