On June 6, 1944, in the face of ferocious German opposition, the Allies successfully landed in Normandy, France. A major reason why the D-Day invasion proved so successful was because of Operation Fortitude, a massive deception plan designed to fool Adolf Hitler and the German High Command.

France had fallen to Hitler's Wehrmacht in June 1940. The next year saw the Germans apparently preparing to invade England, while in reality Hitler was preparing to invade the Soviet Union. As the war in Russia intensified and America joined the conflict, an invasion of Western Europe became a major Allied goal. By 1943, even Hitler conceded that an Allied invasion was just a matter of time, and he began to heavily fortify the coastline of Western Europe, from the Arctic Circle in northern Norway, down the coast of Denmark, Germany, Holland, Belgium, through the length of the Atlantic French coast to the Pyrenees — the Atlantic Wall.

During the Tehran Conference in late 1943, the “Big Three” — Soviet Premier Josef Stalin, British Prime Minister Winston Churchill, and U.S. President Franklin Roosevelt — made preparations for an invasion of France, and even gave it a name, Operation Overlord. Churchill and Roosevelt promised Stalin that the operation would launch the following spring. Overlord would finally open up a second front in Europe and help to take pressure off the beleaguered USSR.

As the German High Command prepared for the coming invasion, two very different schools of thought appeared among the generals. Erwin Rommel, the famed Desert Fox of the North Africa campaign, believed that the only way to stop the Allied invasion was to deny the American and British forces the chance to create a beachhead, effectively destroying them on the beaches as they landed. Rommel's superior, Gerd von Rundstedt, the supreme commander of all German armies in France, believed that Allied superiority in air power and naval guns meant that Rommel's plan was untenable and that a more mobile defense behind the beaches was necessary.

What was at stake in this argument was the operational control of Germany's reserve of panzer forces in France. Germany's tank force and accompanying mobile infantry had been key to Germany's victory over France in 1940, and had been the backbone of the Wehrmacht ever since. The role of these tanks in France would be decisive in defending France from the Allies. Hitler, increasingly micromanaging the war from hundreds of miles away, insisted that he alone would decide how and when these tanks would be used. For the time, Hitler kept them northeast of the Seine River, not far from Pas-de-Calais, the narrowest point in the English Channel and the most obvious invasion point.

Gen. Dwight D. Eisenhower, the supreme commander of the Allied forces, and his staff knew that, despite the Allies' advantages, the Germans could easily win the battle if they knew exactly where the blow would land. Eisenhower's advantage lay in the fact that the German forces in France were spread out over hundreds of miles. If the Germans knew that the Allies were planning to land their forces at Normandy, however, they could concentrate their forces and throw the invasion force back into the sea.

In the book, “D-Day: June 6, 1944, The Climactic Battle of World War II,” historian Stephen Ambrose wrote: “To reinforce the German need to keep their panzer armies northeast of the Seine, (Eisenhower) proposed … an elaborate deception plan. The code name was Fortitude; the objectives were to fool Hitler and his generals into thinking that the attack was coming where it was not, and into believing that the real thing was a feint. Each objective required convincing the Germans that the Allied invasion force was about twice as powerful as it actually was.”

Operation Fortitude had two parts. The first part, “North,” was to convince the Germans that the Allied invasion force was bound for German-held Norway, an important source of raw materials for the Third Reich and the site of many bases for Hitler's U-boats. Early 1944 saw the Allies increase phony army radio traffic in Scotland which was intercepted by the Germans; the creation of a new, unique army — the Fourth British Army — complete with patches worn by soldiers in Scotland that could potentially be seen by Nazi spies; and creation of wooden airplanes that from the perspective of German reconnaissance flights looked like a fleet of bombers parked at Scottish airfields. Additionally, commando raids pinpricked beaches in Norway, giving the Germans the impression that the Allies were doing some reconnaissance of their own.

By May, 13 crack German divisions, along with numerous support personnel, guarded Norway from an impending Allied attack. When Rommel asked Hitler to transfer five divisions to France, the Führer agreed, only to change his mind when German military intelligence offered him another report detailing the apparent Allied preparations to invade Norway.

The second part of “Operation Fortitude,” “South,” was even more important to the allies, and therefore more complicated. This aim of “South” was to convince Hitler that the blow in France would not land at Normandy, but somewhere else. In the book, “D-Day: The Battle for Normandy,” historian Anthony Beevor wrote:

“The most obvious target of all was the Pas-de-Calais. This offered the Allies the shortest sea route, the greatest opportunity for constant air support and a direct line of advance to the German frontier 300 kilometers away. This invasion, if successful, could cut off German forces further west and also overrun the V-1 (rocket) launching sites, which would soon be ready. For all these reasons, the main defenses of the whole Atlantic Wall had been constructed between Dunkirk and the Somme estuary. This region was defended by the Fifteenth Army.”

The Allies wanted Hitler's tanks kept northeast of the Seine, far away from Normandy.

In order to convince the Germans that the true target of the invasion was Pas-de-Calais rather than Normandy, the Allies sent twice as many reconnaissance flights over Pas-de-Calais than over the Normandy beaches. Frogmen and commandos also landed north of the Seine, taking soil samples and gaining intelligence.

Perhaps the most elaborate part of the ruse was the creation of the 1st U.S. Army Group based in East Anglia, positioning it perfectly for an invasion of Pas-de-Calais. Like its phony counterpart in Scotland, this army too generated fake radio traffic that German radio operators in Hamburg believed to be real. The army boasted hundreds of tanks, trucks and artillery pieces — the vast majority of them made out of wood and balloons — with the occasional real one used to create tracks in the mud.

Gen. George S. Patton, regarded by the Germans as America's greatest fighting commander, had been assigned to command this fake army group. Though Patton himself was angry at not being given an active role in the actual invasion, (he had slapped soldiers during his command in Italy, and was being kept out of the action as part of his unofficial punishment), his presence in East Anglia lent considerable weight to the deception.

Absolutely crucial to the success of Operation Fortitude, both “North” and “South,” was the use of spies — not Allied spies but German spies. Since the beginning of the war, Germany had sent spies to England to gather intelligence for the war. By early 1944, virtually all of them had been captured by the British. Rather than execute them outright, the British intelligence service decided to use them. Giving them the choice between working with their captors or dangling at the end of a rope, most of the spies agreed to join the British and began to send phony radio reports back to Berlin.

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This program was named the Twenty Committee, a play on words, since XX also meant double cross. Throughout the war, the British had been feeding their captured German spies just enough intelligence to keep them credible in the eyes of their original German masters, but not enough to jeopardize the war effort. Now, at the war's most crucial juncture in the West, the spies told Germany that the Pas-de-Calais was the target of the invasion.

“Operation Fortitude” proved dramatically successful, as Hitler had become convinced that the landing would be at Pas-de-Calais rather than Normandy. Still insisting on direct operational control over the panzers, Hitler refused to send them to Normandy even after the invasion began, fearing that it was a feint and that the real assault further north was imminent. It was only after several weeks that Hitler acknowledged that the Normandy invasion was the main Allied effort, and sent the tanks in. By that point, however, the Allies in Normandy had their beachhead and had landed massive amounts of men and material.

Without the deception campaign of Operation Fortitude, D-Day almost certainly would have failed.

Cody K. Carlson holds a master's in history from the University of Utah and teaches at Salt Lake Community College. An avid player of board games, he blogs at thediscriminatinggamer.com. Email: ckcarlson76@gmail.com

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