married the sister of Topp's crew mate, Walter Buch. Topp was close enough to be invited to Bormann's residence in Berchtesgaden. Topp's political outlook was not shared by his uncle. His aunt through marriage, Anna Topp, was Jewish. During the Nazi reign, she was sent to and survived the Theresienstadt Ghetto. In his memoirs, Topp claimed not to have believed in Nazi ideology. One analyst wrote, "the contrasts and Topp's individual course make obvious the limitations of any quantitative study" [of his political convictions]. Topp came to terms with the Nazi regime and its crimes postwar. He entered into heated arguments with former comrades over the cause for which they fought. Topp was particularly critical of Admiral Karl Dönitz, commander-in-chief of U-boats and later the Kriegsmarine. After the war, Topp expressed his view that the German naval command, and his superior Karl Dönitz, knew of the Holocaust. Topp referenced Dönitz's commitment to National Socialism, admiration for Hitler, and his presence at the Posen speeches. Topp was critical of Dönitz's pretensions to have been an apolitical soldier. Topp said of Dönitz, that his failure to do anything about it "comes very close to a passive toleration of these insane crimes." Few former U-boat commanders were as vocal in attacking Dönitz's character. His aunt's experiences in the ghetto from 1943 may have been a factor. Dönitz confronted Topp personally when the latter called upon him. He purportedly greeted Topp with a question, "I understand you think I should have been executed?" He presented Topp with his accusation, underlined, and a letter from Samuel Eliot Morison, the official historian of the United States Navy, which accepted Dönitz's defence that he knew nothing of the Nazi crimes. Morison was who told Dönitz of Topp's accusations, or "doubts", as Topp later claimed they were. World War II World War II commenced following the German invasion of Poland on 1 September 1939. U-46, under the command of Sohler, had already been at sea since 19 August, returning to port on 15 September. Topp sailed on three further patrols on U-46 (3 October – 7 November 1939, 19 December 1939 – 10 January 1940 and 11 March – 23 April 1940). During these patrols, U-46 sank one ship of on 17 October and another ship of on 21 December. For his service on U-46, Topp was awarded the U-boat War Badge () on 7 November 1939 and