World War II: The German submarine U-47 sinks the British battleship HMS Royal Oak within her harbour at Scapa Flow, Scotland.

German submarine U-47 was a Type VIIB U-boat of Nazi Germany's Kriegsmarine during World War II. She was laid down on 25 February 1937 at Friedrich Krupp Germaniawerft in Kiel as yard number 582 and went into service on 17 December 1938 under the command of Günther Prien.

During U-47's career, she sank a total of 31 enemy vessels, including the British battleship HMS Royal Oak, and damaged nine more. U-47 ranks as one of the most successful German U-boats of World War II.