At the battle of El Alamein in October 1942, Clarke and his fellow-deceivers convinced the enemy that the thrust of the Allied attack was coming from the south of the battlefront. Trucks covered with tarpaulins that made them look like tanks from the air were drawn up, creating what appeared to be tank tracks in the sand. They laid what looked like a pipeline to an imaginary fuel depot in the south, in fact made from old oil drums. The Germans put two armoured divisions in the south to meet this apparent threat. When the battle came, Montgomery attacked from the north of the battlefront. The battle still took 10 days of heavy fighting but outmanoeuvring the enemy undoubtedly helped bring victory.
A cunning plan
When it came to planning for D-Day, the biggest amphibious operation ever launched, the need for a detailed deception plan was even greater. When discussing the invasion with Joseph Stalin at Tehran, Winston Churchill used the phrase, “In wartime truth is so precious that it should always be attended by a bodyguard of lies.” This perfectly summed up the Allied view of deception.
General Montgomery, since Alamein a keen supporter of deception, was put in charge of the 21st Army Group, effectively making him commander of land forces on D-Day and beyond. His chief deception officer, Lieutenant-Colonel David Strangeways, insisted that the only way to make the Germans keep a large army, their 15th Army, in the Calais region was to convince them that a complete Army Group was forming in Kent, Essex and Suffolk, preparing to invade along the Pas-de-Calais. But how could the deceivers drum up an army of 300,000 men who did not exist?
There were many elements to the deception campaign known as Operation Fortitude. Double agents, German spies who had been sent to Britain and had been turned by MI5, sent back misinformation to their German minders. They played a major role. There were scientific deceptions, too, sending false signals to indicate flotillas of ships or squadrons of aircraft were somewhere they were not.
