Wolfgang Lüth (15 October 1913 – 14 May 1945) was the second most successful German U-boat ace of World War II. His career record of 46 merchant ships plus the French submarine Doris sunk during 15 war patrols, with a total displacement of 225,204 gross register tons (GRT), was second only to that of Korvettenkapitän (Lieutenant Commander) Otto Kretschmer, whose 47 sinkings totaled 273.043 GRT.
Lüth joined the Reichsmarine in 1933. After a period of training on surface vessels, he transferred to the U-boat service in 1936. In December 1939 he received command of U-9, which he took on six war-patrols. In June 1940 he took command of U-138 for two patrols. In October 1940 he transferred again, this time to the ocean-going submarine U-43 for five war-patrols. After two patrols on U-181, the second being his longest of the war, he was awarded the Knight's Cross of the Iron Cross with Oak Leaves, Swords and Diamonds. He was the first of two U-boat commanders to be so honored during World War II, the other recipient being Albrecht Brandi.
Lüth's last service position was commander of the Naval Academy Mürwik near Flensburg. He was accidentally shot and killed by a German sentry on the night of 13/14 May 1945. On 16 May 1945, Lüth was given the last state funeral in the Third Reich.
Lüth was a Baltic German born in Riga, then part of the Russian Empire. He went to the Naturwissenschaftliches Gymnasium there and after he had received his Abitur (certificate), he studied law for three semesters at the Herder-Institut. With his parents' approval he left Latvia to join the German Reichsmarine (renamed Kriegsmarine in 1935) on 1 April 1933 as an officer candidate. After he underwent basic military training, he was transferred to the training ship Gorch Fock attaining the rank of Seekadett (naval cadet) on 23 September 1933. He initially served with the surface fleet, going on a nine-month training tour around the world in the cruiser Karlsruhe from 24 September 1933 to 27 June 1934. He advanced in rank to Fähnrich zur See (midshipman) on 1 July 1934 and served for a year aboard the light cruiser Königsberg (22 March 1936 – 31 January 1937), attaining the rank of Oberfähnrich zur See (senior midshipman) on 1 April 1936 and Leutnant zur See (ensign) on 1 October 1936.
In February 1937 he transferred to the U-boat arm and was promoted to Oberleutnant zur See (lieutenant) on 1 June 1938. In July he was appointed 2nd Watch Officer of U-27 (3 July 1938 – 23 October 1938). He sailed on a patrol in Spanish waters during the civil war in that country on the U-boat tender Erwin Wassner (13 April 1939 – 18 May 1939). In October he was appointed the 1st Watch Officer of U-38 under the command of Kapitänleutnant (Lieutenant) Heinrich Liebe, who during the course of World War II would earn the Knight's Cross of the Iron Cross with Oak Leaves. When war broke out, Lüth was on patrol with U-38 which had left Wilhelmshaven on 19 August 1939 and patrolled the Western Approaches until returning to base on 18 September 1939.
On 30 December 1939 Lüth took command of U-9, a Type IIB U-boat. He went on six patrols with this boat, achieving steady success. In January 1940, U-9 sank the Swedish merchantman Flandria, following the premature ignition of a smoke float. This surface attack was carried out while U-9's bridge was filled with onlooking crew members. Other sinkings included the surfaced French submarine Doris on 9 May 1940 and seven merchant ships with a total of 16,669 gross register tons (GRT). An attack on ORP Błyskawica on 20 April 1940, however, was unsuccessful as the torpedoes malfunctioned and detonated in the wake of the destroyer.
On 27 June 1940 Lüth took command of U-138, a Type IID submarine, with which he sank four ships on his first patrol, totalling 34,644 GRT. In October, U-138 returned from his second patrol, during which it fired a torpedo at (but missed) the Norwegian merchant steamer SS Dagrun (4,562 GRT), sank the British merchant steamer SS Bonheur (5,327 GRT) and damaged the British motor tanker British Glory (6,993 GRT). Initially, the German authorities believed that British Glory had been sunk and Lüth was nominated for the Knight's Cross of the Iron Cross, which he was awarded on 24 October 1940. In the radio announcement, Lüth was credited with sinking 12 ships and one submarine of 87,236 tons, when in reality sunken tonnage added up to only 51,316 GRT by the end of September, rising to 56,643 GRT on 15 October 1940.