Alfred Saalwächter Alfred Saalwächter ( 10 January 1883 – 6 December 1945 ) was a German U - boat commander during World War I and General Admiral during World War II . Early life . Saalwächter was born in Neusalz an der Oder , Prussian Silesia , as the son of a factory manager . He entered the Kaiserliche Marine as a Seekadett on 10 April 1901 , and was trained on the SMS " Moltke " and the SMS " Hertha " . On 29 September 1904 he was promoted to Leutnant zur See . Saalwächter then served with " Bordkommando " units , first with the 2 . Matrosen - Division , then on the SMS " Hessen " with the 2 . Werft - Division . He was promoted to Oberleutnant zur See on 10 March 1906 ; until 1908 , he served with the 2 . Torpedo - Division as adjutant to the I . Abteilung . Saalwächter also served on the SMS " Gneisenau " . Saalwächter served on the SMS " Hannover " in 1910 and later on the SMS " Westfalen " as " Flaggleutnant " to Vice Admiral Hugo von Pohl , commander of the I . Marine - Geschwader . Saalwächter was promoted to Kapitänleutnant on 10 April 1911 and joined the admiralty in Berlin . He remained in the admiralty until 1915 , with his last position there being head of the operations department . In 1912 he received the Order of the Red Eagle . World War I . On 31 March 1915 during World War I , Saalwächter became Flaggleutnant on the SMS " Friedrich der Grosse " , the flagship of the High Seas Fleet . In February 1916 he entered the U - boat service . After graduating from submarine school , he commanded " U - 25 " , " U - 46 " , and " U - 94 " from September 1916 to March 1918 . He was awarded for his success with the Iron Cross 1st Class and the Knight ' s Cross of the House Order of Hohenzollern . Interwar era . In 1920 Saalwächter was named a Korvettenkapitän of the Reichsmarine . He also served on the " Braunschweig " as an admiralty officer . On 1 October 1926 he became commander of the light cruiser SMS " Amazone " , and , a year later , Fregattenkapitän in command of the battleship " Schlesien . Promoted to Kapitän zur See on 15 October 1928 , Saalwächter was chief of staff for Vice Admiral Iwan Oldekop for two years . On 1 October 1932 he became a Konteradmiral and head of the Marinewehrabteilung . On 2 October 1933 Saalwächter was named inspector for naval instruction . During the following five years he had a strong influence on the development of the young officer corps . He was promoted to Vizeadmiral on 1 April 1935 and Admiral on 1 June 1937 . Saalwächter was named commanding admiral of the North Sea naval station at Wilhelmshaven , one of the highest positions in the Kriegsmarine at the time , on 28 October 1938 . On 2 March 1939 , Saalwächter sent a report to the Naval High Command in which he openly discussed the acquisition of bases in Norway . The report stressed both the dangers of to Germany of British dominance in Norwegian waters and the favourable change in the geo - strategic position that a German occupation of Norway would bring about . World War II . With the outbreak of World War II in September 1939 , Saalwächter received command of Marine - Gruppenkommando West and was responsible for operations in the North Sea , which lead to disputes between himself and the fleet commanders , Vice Admirals Hermann Boehm , Wilhelm Marschall , and Günther Lütjens . On 1 January 1940 Saalwächter was promoted to Generaladmiral . Along with Admiral Rolf Carls , Saalwächter had tactical command of Operation Weserübung , the invasion of Norway . He was recognized with the Knight ' s Cross of the Iron Cross on 9 May 1940 . Beginning in summer 1940 , Saalwächter led German surface operations in the North Atlantic and the English Channel , such as Operation Cerberus in February 1942 . On 20 September of that year , he was replaced as head of Navy Group West by Marschall , who was himself replaced by Theodor Krancke in April 1943 . Saalwächter resigned from active service on 30 November 1942 . Saalwächter was imprisoned by the Soviet Union on June 21 , 1945 . He was convicted by a Soviet military tribunal of war crimes on 17 October and executed by firing squad in Moscow on 6 December . In 1994 , after the dissolution of the Soviet Union , Saalwächter was formally exonerated by a Russian court .