

Introduction
Hans Heidtmann (8 August 1914 – 5 April 1976) was a German U-boat commander in World War II and recipient of the Knight's Cross of the Iron Cross of Nazi Germany
U-559 under the command of Heidtmann came under attack by several British warships and an aircraft on 30 October 1942. Fatally damaged and forced to the surface, the U-boat was abandoned after scuttling herself in the Mediterranean. A British boarding party, consisting of Lieutenant Francis Anthony Blair Fasson, Able Seaman Colin Grazier, and Canteen Assistant Tommy Brown, from destroyer HMS Petard recovered the cryptographic materials, but the U-boat sank before the Enigma cipher machine could be brought out. Eight German crewmen and two British seamen were lost, and 37 German survivors were taken prisoner of war.
Awards
- Wehrmacht Long Service Award 4th Class (8 April 1938)
- Spanish Cross in Bronze with Swords (6 June 1939)
- Sudetenland Medal (16 September 1939)
- U-boat War Badge (1939) (26 November 1939)
- Iron Cross (1939) 2nd Class (27 November 1939) & 1st Class (23 September 1941)
- Knight's Cross of the Iron Cross on 12 April 1943 as Kapitänleutnant and commander of U-559