Ernst Mengersen (30 June 1912 – 6 November 1995) was a German naval officer who reached the rank of Korvettenkapitän with the Kriegsmarine during World War II. He was also a recipient of the Knight's Cross of the Iron Cross (German: Ritterkreuz des Eisernen Kreuzes). The Knight's Cross of the Iron Cross was awarded to recognise extreme battlefield bravery or successful military leadership.
World War II
Mengersen commanded the U-18, U-143, U-101 and U-607, and sank twelve ships, including the SS Gairsoppa and HMS Broadwater, on eleven patrols, for a total of 68,071 gross register tons (GRT) of Allied shipping. The Gairsoppa carried 7,000,000 ounces of silver, which was worth £600,000 at the time of its sinking.
Two Knight's Cross of the Iron Cross recipients served as watch officers under Mengersen's command. Egon-Reiner von Schlippenbach served as first watch officer on U-101's fourth patrol under Mengerson, while Karl-Heinz Marbach was Mengerson's second watch officer on U-101.
In June 1943 Mengersen became commander of the 20th U-boat Flotilla based in Pillau, remaining in this position until 24 February 1945. During the last three months of the war, Mengersen served firstly with the 25th U-boat Flotilla and then in April 1945, he was selected to command the new 15th U-boat Flotilla.
Wehrmacht Long Service Award, 4th class (1 April 1937)
Spanish Cross in Bronze with Swords (23 October 1940)
Iron Cross (1939)
2nd Class (27 January 1940)
1st Class (10 December 1940)
U-boat War Badge (1939) (25 February 1942)
Knight's Cross of the Iron Cross on 18 November 1941 as Kapitänleutnant and commander of U-101
Mentioned in the Wehrmachtbericht on 3 December 1940
War Merit Cross
2nd Class (1 September 1944)
1st Class (31 January 1945)
Mengersen survived the war and died in Detmold, at the age of 83.