About Gustav Sieß
Lived 1883 – 1970 (aged 86). Gustav Sieß was a German military personnel.
Generalleutnant Gustav Sieß (born 11 December 1883 in Hamburg – died 14 October 1970 in Hamburg) was a Kapitänleutnant of the German Kaiserliche Marine during World War I and Oberstleutnant in the Luftwaffe during World War II. He is most known for being the commander of the U-73 which lay the mine that sank RMS Titanics sister ship HMHS Britannic on 21 November 1916. Sieß sank a total of 53 ships and 3 warships during his career in the Kaiserliche Marine worth 188,295 tons, making him the 6th most successful submarine commander of World War I.
Early Career
Sieß joined the German Kaiserliche Marine as a Seekadett on 1 April 1902 and was trained aboard the training ship SMS Moltke and in the Naval Academy in Mürwik. After completing his training in October 1904, Sieß served aboard the armored cruiser SMS Hansa in Southeast Asia for two years before returning to Germany with the rank of Leutnant zur See. Upon his return in 1906, Sieß became a company officer in the 1st Torpedo Division in Kiel while also serving as watch officer on various torpedo boats for another two years. In 1908, Sieß was transferred to the mine warfare division in Cuxhaven and held the command over minesweepers S-27, S-25 and S-38 before being promoted to Oberleutnant zur See on 30 March 1908. From 1 October 1910 until November 1912, Sieß served as adjutant to the Inspectorate of Coastal Artillery and Mine Warfare whereupon he gained a posting as a company officer in the 2nd Torpedo Division in Wilhelmshaven. During this time, Sieß obtained the command of the torpedo boat SMS V3 before also commanding the SMS V1. Sieß was promoted to Kapitänleutnant on 12 April 1913 and saved a crew member from drowning that same year. For his heroic actions, Sieß was awarded the Lifesaving Medal which was personally handed to him by Kaiser Wilhelm II.
Interbellum Following the end of the war on 11 November 1918, Sieß was placed at the disposal of the Kaiserliche Marine and appointed commander of the 9th Minesweeping Half-Flotilla on 1 April 1919. On 28 August 1919, Sieß was placed at the disposal of the commander of the Marinestation der Ostsee before being discharged from the Navy on 11 November 1919. Sieß was awarded the honorary rank of Korvettenkapitän on 22 February 1920 for his service during the war. In his civilian life, Sieß formed a commercial company (Siess, von Loë & Co.) and served as a board member of Klein-Michel-Motorbau AG in Hamburg in 1925. Sieß was also a member of the Stahlhelm-Fraktion and led the Hamburg district naval department. After receiving training to become a pilot in 1935, Sieß returned to military service as a Major in the Luftwaffe and became head of logistics at the Reich Air Ministry in Berlin. Sieß also served as deputy commander of Air Ordnance Group 1 until becoming its commander following his promotion to Oberstleutnant on 18 January 1938.
World War II Following the outbreak of World War II in 1939, Sieß retained his position in the Ministry and was transferred to active service following his promotion to Generalmajor on 1 November 1940. After falling seriously ill, Sieß was transferred to the Führerreserve on 23 September 1943 and promoted to Generalleutnant on 1 April 1944 before Sieß was discharged from military service on 30 April as his health had not improved. After the end of the war in 1945, Sieß was arrested by Soviet troops on 15 June 1945 and sentenced in court to 25 years in prison.
Later Life & Death
Despite his original prison sentence, Sieß was released after serving only ten years on 8 October 1955 and returned to his home in Hamburg where he died on 14 October 1970 at the age of 86. He was buried at the Ohlsdorf Cemetery in Hamburg.
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Important facts
People in Gustav Sieß's life
Named in this biography and alive at the same time
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Frequently asked questions
Who was Gustav Sieß?
German Generalleutnant (1883-1970)
When was Gustav Sieß born?
Gustav Sieß was born on 11 December 1883 in Hamburg.
When did Gustav Sieß die?
Gustav Sieß died on 14 October 1970 in Hamburg.
What was Gustav Sieß's occupation?
Gustav Sieß was a military personnel.
What nationality was Gustav Sieß?
Gustav Sieß was German.
Sources & further reading
Cite this page
APA: Biography.guide. (2026). Gustav Sieß. https://biography.guide/gustav-siess/
MLA: "Gustav Sieß." Biography.guide, https://biography.guide/gustav-siess/.
Chicago: "Gustav Sieß." Biography.guide. https://biography.guide/gustav-siess/.
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