The Germans knew that at some stage the Allies would launch a cross-Channel invasion, but they were unsure of exactly where or when it would take place. As a crucial part of their preparations forD-Day(6 June 1944), the Allies developed a deception plan to draw attention away from Normandy.
The D-Day deception plan was codenamed Operation ‘Fortitude’ and was part of a larger overall deception strategy – Operation ‘Bodyguard’. ‘Fortitude’ consisted of two parts: ‘Fortitude North’ was meant to fool the Germans into thinking that the Allies would launch an attack on Norway, and ‘Fortitude South’ was designed to convince the Germans that an invasion would occur north-east of Normandy in the Pas de Calais.
Dummy tanks
© IWM H 42531
Inflatable Sherman tank used for deception during the Second World War.
Real tanks were replaced by dummy tanks when they were moved from their holding areas. The inflatable decoys made the Germans think the Allies had more tanks than they actually did and helped mask that final preparations were being made for the invasion.
The deception techniques used in preparation for D-Day had previously been used in North Africa in 1941-1942 and prior to the landings in Italy in 1943.
First US Army Group (FUSAG)
As part of ‘Fortitude South’, the Allies created the fictitious First US Army Group (FUSAG), an imaginary force ‘based’ in south-east Britain. This also helped give the impression that the invasion force was larger than it actually was. Fake radio traffic and decoy equipment – including inflatable tanks and dummy landing craft – mimicked preparations for a large-scale invasion aimed at the Pas de Calais.
Double agents delivered false information to reinforce this deceit both before and after the Normandy landings. The most famous of these agents, Juan Pujol Garcia (‘Garbo’), invented a network of imaginary agents who were supposedly supplying him with information on Allied preparations.
Operations 'Taxable' and 'Glimmer'
© IWM E(MOS) 1451
A factory worker producing foil code-named WINDOW which was dropped by allied aircraft to jam enemy radar.
In Operations ‘Taxable’ and ‘Glimmer’, the RAF dropped metal strips – codenamed ‘Window’ – along the French coast to confuse German radar. On the night of 5-6 June, as part of Operation ‘Titanic’, the RAF dropped dummy parachutists to simulate an airborne invasion and draw German forces away from key objectives.
Metallised strips of 'Window' caused confusion on German radar.
Allied air power also played an important part in the deception. In the months leading up to D-Day, Allied bombers attacked road and rail networks in an attempt to isolate the invasion area, but additional attacks were made on other parts of northern France to divert German attention away from Normandy.
The Allied deception strategy for D-Day was one of the most successful ever conceived. The Germans overestimated the strength of Allied forces in Britain, particularly in the south-east, and believed as late as July 1944 that a larger second invasion would land in the area around Calais. This helped the Allies achieve the key element of surprise and kept German reinforcements away from Normandy both on D-Day and in the weeks that followed.
Related content
© IWM (MH 3660)
D-Day
The 'Funny' Tanks of D-Day
These unusual vehicles played an important role in theD-Daylandings, the Battle of Normandy and the campaign in north-west Europe.In early 1943, the 79th Armoured Division under the command ofMajor-General Sir Percy Hobartwas given responsibility for developing equipment and tactics to perform specialised tasks in support of ground troops on and after D-Day.
© NARA
Second World War
The Lies and Deceptions that made D-Day possible
On Tuesday 6 June, 1944, nearly 160,000 allied soldiers landed along a 50-mile stretch of coast in Normandy. Thanks to a series of deception efforts undertaken by the Allies, the bulk of Germany’s defensive forces were 150 miles away from Normandy when the landings were taking place.
© IWM (H 39178)
D-Day
How D-Day Was Fought From The Air
Shortly after midnight on 6 June, over 18,000 men of the US 82nd and 101st Airborne Divisions and the British 6th Airborne Division were dropped into Normandy. Allied paratroopers and glider-borne infantry were well trained and highly skilled, but for many this was their first experience of combat.
© IWM
First World War
Why the British Army built fake trees during the First World War
During the First World War, Allied soldiers needed a way to see without being seen. The solution was the camouflage tree, a fake piece of shrubbery with an observation post hidden inside. Initially a French invention, the camouflage tree would allow Allied soldiers to keep track of enemy movements from a concealed elevated position.
Atlantic wall image from Bundesarchiv, Bild 101I-719-0240-05 / Jesse / CC-BY-SA 3.0.
D-Day
D-Day on land: The Allied Landings in Normandy
The land assault on Nazi-occupied France would determine the success or failure of the entire D-Day campaign. Join IWM Curator Adrian Kerrison at IWM Duxford to explore the story of the land battle for Normandy.
