About Günther Prien
Günther Prien (16 January 1908 – presumed 8 March 1941) was a German U-boat commander during World War II. He was the first U-boat commander to receive the Knight's Cross of the Iron Cross and the first member of the Kriegsmarine to receive the Knight's Cross of the Iron Cross with Oak Leaves of Nazi Germany. It was Germany's highest military decoration at the time of its presentation to Prien. Under Prien's command, the submarine U-47 was credited with sinking over 30 Allied ships totalling about 200,000 gross register tons (GRT), along with the British battleship HMS Royal Oak at anchor in the Home Fleet's anchorage in Scapa Flow. Prien died when U-47 was lost on 8 March 1941. On 11 May 1936, Prien was appointed first Watch Officer on U-26, serving under the command of Werner Hartmann after forming a bond at the training school. World War II commenced during Prien's first patrol in U-47, following the German invasion of Poland on 1 September 1939. In 1931 he became first mate and attended school for a commission.
Biography source: Wikipedia. The profile adds birthday-specific historical context from the Celebs Birthday Today editorial database.