In what year was the man under whose command the 1st U-boat Flotilla was founded born?
Karl Dönitz Karl Dönitz (sometimes spelt Doenitz) (] ; 16 September 1891 – 24 December 1980) was a German admiral who played a major role in the naval history of World War II. Dönitz briefly succeeded Adolf Hitler as the head of state of Germany.
Walther Schwieger Kapitanleutnant Walther Schwieger (7 April 1885 – 5 September 1917) was a U-boat commander in the Imperial German Navy ("Kaiserliche Marine") during First World War. In 1915, he sank the passenger liner  with the loss of 1,198 lives.