Karl Doenitz developed the German submarine service, commanded his country’s navy in the final years of World War II, succeeded Adolf Hitleras chancellor of Germany, and negotiated the final surrender. As one of the most significant innovators and advocates of submarine warfare, Doenitz established tactics and procedures that were adopted around the world.
Born on September 16, 1891, in Grunau, near Berlin, Doenitz became interested in the military at an early age and in 1910 entered the Imperial German Navy’s training school. He gained a commission in 193 and served with the German surface fleet before joining the newly formed submarine, or U-boat, service in October 1916. After serving aboard the u-68 as a watch officer, Doenitz assumed command of the boat. During a night attack against a British convoy on October 4, 1918, escort vessels sank the U-68 and captured Doenitz and most of his crew.
After his repatriation in 1919, Doenitz was one of the few officers retained in the small German navy allowed by the terms of the Versailles Treaty. Because the armistice forbade a German submarine force, Doenitz served in a succession of surface commands during the postwar years. With the rise of Hitler and his “Z Plan” of immediate naval expansion, which included submarines, Doenitz returned to the U-boats. On September 27, 1935, the naval commander in chief, Adm. Erich Raeder, ordered Doenitz to rebuild and command the new U-boat fleet. When Doenitz assumed command, the Germans had no submarines, crews, operational manuals, or tactical doctrine.
Relying on his personal experience and his study of emerging submarine strategy from other countries, Doenitz literally “wrote the book” on German submarine warfare. In addition to overseeing boat design, including weapons and propulsion systems to increase speed and range, Doenitz personally wrote crew-training manuals. He also devised the two primary concepts of U-boat doctrine. Doenitz determined, and convinced his superiors, that the primary targets of U-boats should be merchant vessels rather than warships in order to cut enemy supply lines. His second concept, one that would revolutionize submarine warfare, was that U-boats should deploy and fight in groups or teams that he called “wolf packs.”
Having to compete with the surface navy and the army for the limited German steel resources slowed Doenitz’s objective of establishing a three hundred-boat submarine fleet. When World War II began, on September 1, 1939, Doenitz had a mere fifty-six U-boats, only twenty-two of which were capable of operating in the open Atlantic. Doenitz had to deal not only with a limited fleet but also with the conventional restrictions of having to warn potential targets before firing to allow crews to evacuate. Even so, his U-boats sand 114 merchant vessels in the last four months of 1939.
Launching more submarines as resources became available, Doenitz focused on isolating Great Britain from resupply by sea and also supported German amphibious operations. In August 1940, Hitler lifted his prewarning requirements, allowing Doenitz to proactive unrestricted submarine warfare. In a four-month period, the U-boats sank 185 ships totaling more than a million tons.
The entry of the United States into the war in December 1941 opened up a new, lucrative target source, for the Americans had no defensive plan for their convoys to England. In the first six months of 1942, the U-boats sent 585 U.S. ships to the bottom of the Atlantic, many only a few miles off the American coast.
On January 30, 1943, Doenitz, now a full admiral despite never having joined the National Socialist Party (Nazis), became the German navy commander. In addition to his new responsibilities, he remained personally in charge of the growing U-boat force as it faced new challenges. The Allies, with their increasing number of men and improved weapons, gained the advantage on both land and sea. Radar now detected the submarines, and the Allies broke the German secret codes, revealing wolf-pack locations.
Doenitz attempted to counter the Allied advances with snorkel systems that allowed submarines to recharge their batteries while submerged and by continuing to upgrade engines and torpedo systems. These improvements proved to be too little too late. The German U-boats, which had nearly won the Battle of the Atlantic in 1942, were by 1944 all but ineffective in limiting cross oceanic shipping. Nonetheless, Doenitz, and his U-boats continued to fight, with 398 U-boats still operational at the end of the conflict. The U-boats’ accomplishments had not come cheaply. Germany lost more than thirty-two thousand sailors and 781 submarines.
Doenitz’s service to Germany did not conclude with the end of the U-boats and the navy. Hitler, before committing suicide on April 30, 1945, left instructions for Doenitz to succeed him as chancellor. The former U-boat captain immediately attempted to negotiate a separate peace with the Western powers and bring the war to a close so as to minimize further casualties and to preserve some independence for Germany. His efforts failed, and on May 7, he authorized an unconditional surrender.
Doenitz remained the titular head of Germany for two weeks before his arrest as a war criminal on May 22. Although he had never joined the Nazi Party and several American naval leaders testified that they, too, practiced unrestricted submarine warfare, he was convicted of the rather ambiguous charge of committing crimes against peace. He served ten years with other German war criminals in Spandau Prison before being released to live out the rest of his life in retirement in Hamburg. He died of heart disease at the age of eighty-nine on December 24, 1980. Along with the decade in prison, Doenitz suffered the loss of both of his sons, who died in naval combat during the war.
Doenitz was a brilliant U-boat commander and a visionary who could see the submarine’s contribution to warfare. Although undemonstrative in public, he believed passionately in U-boats and felt genuine affection for their crews. His innovations in submarine warfare, especially in the “wolf pack” tactic, became standard throughout all navies. Although nuclear power and weapons a decade later changed many of Doenitz’s tactics, the professionalism and spirit of the German U-boat fleet has left an indelible mark on submarine forces around the world.