Karl-Friedrich Merten (15 August 1905 – 2 May 1993) commanded the U-boat in Nazi Germany's Kriegsmarine during World War II. He received the Knight's Cross of the Iron Cross with Oak Leaves. Merten was credited with the sinking of 27 ships for a total of of Allied shipping. Merten joined the Reichsmarine (navy of the Weimar Republic) in 1926. He served on the light cruisers Karlsruhe and Leipzig during the Spanish Civil War patrols.
At the outbreak of World War II, he was stationed on the battleship , participating in the Battle of Westerplatte and Battle of Hel. He transferred to the U-boat Arm in 1940, at first serving as a watch officer on before taking command of U-68 in early 1941. Commanding U-68 on five war patrols, patrolling in the Atlantic Ocean, the Caribbean Sea and the Indian Ocean, he was awarded Knight's Cross of the Iron Cross on 13 June 1942 and the Oak Leaves to his Knight's Cross on 16 November 1942. On the second patrol, Merten helped rescue the crews of the auxiliary cruiser Atlantis and the refuelling ship Python, which had been sunk by the Royal Navy. In January 1943 Merten became the commander of the 26th U-boat Flotilla and in March 1943, Merten was given command of the 24th U-boat Flotilla. In February 1945, he was posted to the Führer Headquarters in Berlin. At the end of the war, he was taken prisoner of war by US forces and released again in late June 1945.
After the war, Merten worked in salvaging sunken ships in the Rhine river. In November 1948, Merten was arrested by the French and accused of allegedly wrongful sinking of the French tanker Frimaire in June 1942. He was acquitted and later worked in the shipbuilding industry. Merten, who had written his memoir and books on U-boat warfare, died of cancer on 2 May 1993 in Waldshut-Tiengen, Germany.
Early life and career
Merten was born on 15 August 1905 in Posen, in the Prussian Province of Posen in the German Empire, present-day Poznań, Poland. His father was Dr. jur. Karl-Friedrich Merten, who in 1910 became the mayor of Elbing, present day Elbląg. In 1934, he was forced out of office when he refused to join the Nazi Party. Merten had a sister and a brother, both died before he had turned seven. His younger brother Klaus, as a Feldwebel (staff sergeant) in a pioneer platoon, died in 1942 of wounds sustained on the Eastern Front. Aged thirteen, Merten joined the Königliches Preußisches Kadettenhaus (Royal Prussian Cadet House) in Köslin, present-day Koszalin, on 1 April 1918. Following World War I, the cadet house was transformed into a state-run boarding school. There, he attended the school from 1920–26 and graduated with his Abitur (university entry qualification) on 20 March 1926.
He joined the Reichsmarine on 1 April 1926 as a member of "Crew 26" (the incoming class of 1926). He underwent basic military training with the 5th company of the 2nd department of the standing ship division of the Baltic Sea on the Dänholm in Stralsund. Merten was then transferred to the training ship Niobe (12 July – 17 October 1926), attaining the rank of Seekadett (officer cadet) on 12 October 1926. Following a 17-month stay on board the cruiser Emden (18 October 1926 – 24 March 1928), he advanced in rank to Fähnrich zur See (midshipman) on 1 April 1928.
Merten sailed on Emdens first training cruise, which began on 14 November 1926 and started in Wilhelmshaven. The journey took him and her crew around Africa to Indonesia and the Cocos Islands where was lost on 9 November 1914. There the crew held a commemoration on 15 March 1927. The journey then continued to Japan and Alaska down the west coast of North and South America, around Cape Horn. They celebrated Christmas and New Year's Day in Rio de Janeiro. From there they headed to Middle America and the Azores. Their final stopover was Vilagarcía de Arousa, Spain before they returned home on 14 March 1928.