1944 D-Day Operation Overlord - Planning of The Invasion

Planning of The Invasion

Allied forces rehearsed their roles for D-Day months before the invasion. On 28 April 1944, in south Devon on the English coast, 638 U.S. soldiers and sailors were killed when German torpedo boats surprised one of these landing exercises, Exercise Tiger.

In the months leading up to the invasion, the allied forces conducted a deception operation, Operation Fortitude, aimed at misleading the Germans with respect to the date and place of the invasion.

There were several leaks prior to or on D-Day. One such leak was the crossword that came out in The Herald and Review six days before the beach landings were to take place. Some of the answers consisted of Overlord, Neptune, Gold and other key terms to the invasions; the US government later declared that this was just a coincidence. Through the Cicero affair, the Germans obtained documents containing references to Overlord, but these documents lacked all detail. Double Cross agents, such as Joan Pujol (code named Garbo), played an important role in convincing the German High Command that Normandy was at best a diversionary attack. U.S. Major General Henry Miller, chief supply officer of the US 9th Air Force, during a party at Claridge's Hotel in London complained to guests of the supply problems he was having but that after the invasion, which he told them would be before 15 June supply would be easier. After being told, Eisenhower reduced Miller to lieutenant colonel and sent him back to the U.S. where he subsequently retired. Another such leak was General Charles de Gaulle's radio message after D-Day. He, unlike all the other leaders, stated that this invasion was the real invasion. This had the potential to ruin the Allied deceptions Fortitude North and Fortitude South. For example, Gen. Eisenhower referred to the landings as the initial invasion.