Operation Fortitude: The Plan That Fooled Hitler

Strategic Deception: A New Concept

In 1944, so-called 'strategic deception' was still a relatively new concept. It was the brainchild of Lieutenant-Colonel Dudley Clarke, a veteran of the North African campaign. Working in Cairo, he organised the construction of a fake Alexandria Harbour, successfully diverting German bombers from the real one, several miles away.

D-Day was the perfect arena for such subterfuge. Everyone knew the invasion would occur in one of two locations—the Normandy beaches or the Pas-de-Calais. The British reasoned that the more troops the Germans poured into one area, the weaker they left the other. All the Allies had to do was fool the Axis powers into picking the wrong location.

The real D-Day plan was an invasion of Normandy. The fictitious plan was to make them think that the attack was coming in the Pas de Calais. And so, they knew what we've got to make the Germans think. The bigger question was: How do we do that?

Jonathan Trigg, author of D-Day Through German Eyes

Building A Fake Army

So began the most elaborate strategic deception in military history—Operation Fortitude. Just like the genuine invasion plan, Operation Overlord, the fake one was unbelievably complex. Firstly, the Allies created the US First Army Group—an enormous military force that did not actually exist. Next, they constructed tanks and amphibious vehicles out of inflatable rubber, steel drums and balsa wood. Up close, they were not very convincing, but they passed for the real thing from the air.

Inflatable Sherman tank The Luftwaffe pilots would fly over the coast and see these huge formations of tanks on the coastline, then go back and report back to German headquarters. What they didn't realise was that these were fake tanks!

Giles Milton, author of D-Day: The Soldiers’ Story

Everyone knew D-Day would require air support, so that meant Fortitude needed aeroplanes, too. Flimsy wooden aircraft were soon lined up on fake airfields, with supposed landing strips marked out by lights. At nighttime, it even looked like the aeroplanes were moving. A team of burly men dragged car headlamps back and forth to give the impression of activity on the runways. No expense was spared in making the illusion as convincing as possible. There were fake army camps, filled with empty tents, fake tanks made of inflatable rubber, and even a phoney dock facility in Dover, assembled by a team of set-builders from Shepperton Studios.

With physical trickery in place, it was time to turn to other areas. Fake radio transmissions were sent out on the airwaves, detailing Allied plans for the (non-existent) attack on the Pas de Calais, knowing German radio operators would be picking them up.

This was an era where fake news came into its own.

Giles Milton, author of D-Day: The Soldiers’ Story

In these transmissions, they claimed that the feared Allied general, George S Patton, was in command of the fake army. Since the Germans believed that Patton would be leading the invasion, seeing him positioned near Pas de Calais convinced them this would be the invasion site. In reality, Patton was not directly involved in D-Day.

The Germans thought that Patton was the best that we had. So, wherever Patton was, that was where the action was going to be.

Jonathan Trigg, author of D-Day Through German Eyes

False Information

With less than two weeks before D-Day, German General Hans Cramer was released from a prisoner-of-war camp during a prisoner exchange. The Allies drove him around what they claimed was the area where Patton's army was stationed near Pas de Calais. However, they had actually taken him 100 miles away to Kent and Sussex, where the real D-Day invasion forces were gathering. Cramer never realised he had been tricked, and when he returned to Germany, he reported seeing massive forces preparing to invade Pas de Calais.

What they decided to do was to drive him through the area where all of this real activity for D-Day was taking place. They drove him through south-west England to have him repatriated, but what they did was make him think he was driving through south-east England. So, they put a corporal in the car with him who kept making references to different places they were, which were in south-east England. They changed all the road signs on the way. And so when Cramer got back to Germany, he hurried to see his old friend Rommel and told him, “It's coming in the Pas de Calais!”

Joshua Levine, author of Operation Fortitude: The Greatest Hoax of the Second World War

Using a German general to feed the enemy false information was an inspired move. After all, they were far more likely to credit intelligence that came from one of their own. By convincing the German High Command that the main Allied invasion would occur at Pas-de-Calais, the Allies achieved strategic surprise on D-Day. German forces were spread thin, with significant reinforcements held back from Normandy in anticipation of an attack at Pas-de-Calais that never materialised. This allowed Allied forces to establish a foothold in Normandy and begin the liberation of Western Europe.

Operation Fortitude remains one of the most successful deception operations in military history. It demonstrated the effectiveness of strategic deception in warfare and highlighted the importance of psychological operations in shaping the battlefield. The lessons learnt from Operation Fortitude continue to inform military strategy and tactics to this day, serving as a reminder of the power of deception in the art of war.