- Second World War (1939-1945)
- Oberleutnant zu See der Reserve
- Kommandant, "U 997", 14. Unterseebootsflottille, Kriegsmarine
- Awarded on:
- May 11th, 1945
Author Clemens Range dates Hans Lehmann's Knight's Cross on 8 June 1945, thus after the effectiveness of the Dönitz-decree. Walther-Peer Fellgiebel, author of Die Träger des Ritterkreuzes des Eisernen Kreuzes 1939–1945, indicates that Lehmann received the Knight's Cross on 11 May 1945, before the Dönitz-decree prohibited the awarding of the Knight's Cross. Scherzer dates the Knight's Cross on 7 May 1945.