'Top Secret' maps reveal the massive Allied effort behind D-Day

Operation Overlord was shielded from the Germans by Operation Bodyguard, inspired by Churchill’s remark that truth in wartime should always be “attended by a bodyguard of lies.” That meant simulating preparations for landings elsewhere to keep German forces dispersed. The tactical deceptions underpinning Bodyguard included dropping dummies by parachute, such as this one, to distract Germans from incursions by real paratroopers.

While planners for Overlord produced detailed maps of Normandy, the masterminds of Bodyguard concocted a fictional invasion force: FUSAG (First U.S. Army Group). General Patton (left) posed as FUSAG's chief until he took charge of a real army in France in July 1944.

Props for the Bodyguard hoax also included fake warplanes that were placed where German reconnaissance pilots might spot them. FUSAG supposedly consisted of 50 divisions preparing to cross the Strait of Dover after Gen. Montgomery's diversionary landing at Normandy

The FUSAG deception was sustained by cunning double agents like Spaniard Juan Pujol, who had enlisted as a German spy with the intention of serving the Allies. He filed false reports that helped keep German troops tied down at Calais.