D-Day Intelligence and Espionage (1943-44)

Figure 1.--.

The Allied cross-Channel invasion could not be hidden. The Germabns knew it was coming. The invasion and inherent logic of such an opetation simply could not be hidden. What was not known, however, was when and where. The answer to these two questions became a top priority for Abwehr espionage operations. Only, unbenongst to the Abwehr, the British had penetrated the German spy network with their Double Cross operation. The result was that the informtion received and presented to Hitler was provided by MI-5 and carefully designed to deceive. The Allie were able to leaern a great deal about the German preprations to repell the invasion--the Atlantic Wall. This came from aerial reconisance, the French resistance, amd Ultra intercepts. The Germans were, however, to learn much less about Allies invasion preparationd. Allied conttol of the air was so overwealming that they could easily photograph the entire reach of the Atlntic Wal. The Germans on the other hand were very limited in their aerial surveilance activities. And measures were taken so that the aerrial reconisance findings condorned the missinformation fed to the Germans by the Double Cross opetation. And this was Operation Fortitude, the effort to concvuince the Germans that the Allies were massing a huge army in Kent for a cross-Channel invasion at the Pas de Calais, the most obvious location for the crossing. As a result of the Allies intelligence operation, the Alliies knew a great deal about the Germans and their preparation to repel the Allied invasion that everyone knew was coming. There are few instances in important battles where one force knew so little about the other side and one side so much.


The Britisg Double-Cross opetation proved to be a key component of the Opertation Fortitude deception. The British from an early point identifified the German spies. They werte give the choice of execution as spies or becoming double asgents for the British. The primary Double-Cross objective was to convince the Abwehr that the Allies would cross the Channel at the Pas de Calais with a secondary effort aimed at Norway. The MI-5 handlers were a coloful lot. The best known were a Serbian play boy, a Polish pilot, a Peruvian party girl, an excentric Spaiard (perhaps the most important), and a dog-lovibng French woman. [Macintyre] A sixth Double-Cross handler has recently been idenified. In the end, Hitler kept a large part of his forces waiting the allies, including powerful SS Oanzer divisions awaiting the Allied Airst Army in the Pas de Calais whike the fate oif the Reich was bding decided in Normandy. What is most amazing is that the Double0Cross agents were so convincing that Hitler kept these powerful forced in the Pas De Calais even after the D-Day invasion. Thdy convinced him that Normandy was a feuint abnd the main force was preparing to land at the Pas de Calais.


The ultra code breakers at Blechley Park collected a vast amount of information about the Wehrmacht forces in France. By analizing the German housekeeping traffic, the allies were able to learn a great deal about the German order of battle. The allies knew where most German divisions and oither units were posistioned and their relative size and strength.

French Resistance

Photo Reconissance

Operation Fortitude Diversion

The most logical place for the Allied invasion was the Pas de Calis. It offered the shortest sea trip and broad sandy beaches. It was also the shortest, most direct route into Germany. The Allies deception campaign to protect the Normandy landings was to convince the Germans that what seemed to be logical cite of the landings was indeed where the Allies would strike. [Holt} General Patton was given the assignment of staging a diversion with the non-existent First U.S. Army Group in Kent. The Germans were convinced that Patton would lead the invasion. Radio traffic was generated and dummy tanks and trucks deployed. There were, however, many other diversions. Patton in Kent was just opposite the Pas de Calais, helping to confirm the German assessment that the invasion would come there. The fact that Patton was in Kent was a factor in convincing the Germans that this was where the main strike would come because the Germans assumed that Patton would command the found forces. Some historians have argued that this was a misuse of Patton. (Patton had been sidelined but no fired by Eisenhower after the slapping incident in Sicily.) Omar Bradley was a competent general. He was not a brilliant commander. The breakout in Normandy may have come earlier if Patton was in command. [Hanson] It seems incredible today given the size of the Overlord landing force that the Germans could have been deceived. It shows not only the Allies mastery of the skies prevented German areial surveilance, but that the Germans had no unturned agents in southern England.


Macintyre, Ben. Double Cross: The True Story of the D-Day Spies.


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Created: 1:48 AM 7/31/2012
Last updated: 1:48 AM 7/31/2012