Karl Dönitz was born in Grunau, near Berlin, Germany in 1891 and was the son of Emil Dönitz and Anna Beyer. During World War I he served as a Leutnant zur See (acting sub-lieutenant) in the Mediterranean and was promoted to Oberleutnant our See in 1916, however he was captured and imprisoned by the the British at Malta the following year.
World War II
In 1943 Dönitz became Commander in Chief of the Navy, having served as a submarine commander since the outbreak of the war. During the final days of the war in 1945, Hitler, who felt betrayed by Heinrich Himmler and Joseph Goebbels, named Karl Dönitz his successor in his final will and testament, though he denied him the title of Fuhrer. Following Hitler's suicide, Dönitz became the leader of Germany and surrendered to the Allies on the 7th May, 1945.
In the immediate aftermath of the war, Karl Dönitz was allowed to remain in power, though he had no territorial authority. His cabinet, known as the Flensburg Government, met daily until the 22nd May when the British arrested Dönitz as a prisoner of war.