World War II/Operation Fortitude

Operation Fortitude was the collective codename for a number of the deception operations used by the Allied forces prior to and following the Normandy landings. Fortitude had two forms: Fortitude North, which was to instill in Hitler and the German generals a fear of an amphibious landing in Norway?, and, more significantly, Fortitude South. The principal aim of Fortitude South was to trick the German high command into believing that the landings would take place in the [Pas de Calais]? rather than the Normandy beaches.

The deceptions used in Fortitude South were manifold. These ranged from the building of artificial airfields complete with papier-mache aircraft in East Anglia, to radio traffic deception by a specially briefed outfit which drove around the south-coast of England simulating an army manouevring, to the broadcasting of misleading messages from secret agents who had effectively been 'turned' by the Double Cross System, such as Garbo.

The Allies were able to judge fairly easily the effectiveness of these strategies since they had cracked the German code-system fairly early in the war (see Enigma), and were thus able to decrypt the German high command's responses to their purported overtures. They maintained the pretence of a staged landing at the Pas de Calais for some considerable time after D-Day?, possibly even as late as September 1944. This was vital to the success of the Allied plan since the uncertainty which this caused forced the Germans to keep much of their reserve force bottled up, waiting for an attack which never came, thus allowing the Allies to maintain their marginal foothold in Normandy whilst building up their forces.