"Great D-Day Deception"
Released : Apr 2, 2012
by WW2 Bletchley Park Codebreaker, Mavis Batey.
Ben Macintyre’s new book on Double Cross tells the amazing story of how our double agents were made to tell the German High Command that the imminent invasion would take place at the Pas de Calais and their relationship with their case officers is of particular interest. But why were the Germans so easily convinced that we were going to land at Calais? Hitler was already well aware that after the disaster at Dieppe in August 1942, when we had attempted to land on open beaches, we would in future choose a landing place with a harbour, as we did at Algiers in the North African landings; the chosen area of the Seine bay around Bayeux in Normandy for D-Day was most unlikely for invasion, as it was so far from a large port. At a meeting immediately after Dieppe it had been suggested that if we could not capture a port we should take our own floating harbour across the Channel with us; this was heard with derision until it came to Churchill’s notice.The supporting mulberry harbour floated to Arromanches, where the British and Canadian D-Day troops landed on open beaches was named Port Winston in his honour. In his history of WW2 Churchill said that the sacrifice of Dieppe was not in vain.
Bletchley Park had also made a great contribution as my boss, Dilly Knox, had at the end of 1941 broken the Enigma machine used by the German Secret Service (Abwehr) on which the London Controlling Section in charge of Double Cross depended. My section’s report on how this was done has only recently been released by GCHQ. Bletchley Park holds 140,000 messages on what we called the Spy machine and I must have handled many thousands of them.The double agents under the supervision of their case officers sent out messages in a simple code on their own wireless sets to their unsuspecting controllers in Madrid or Lisbon, who would then pass on the misinformation to Berlin on the Enigma machine and we then knew which baits were being swallowed and which agents were trusted most. It was the questions asked back to the double agents along the same route which were so important for the D-Day Operation Bodyguard. SCHAEF’s main anxiety was whether the harbours being constructed piecemeal in the Southampton area had been spotted as it would have been obvious that they and the pipelines were destined for Normandy. We were able to reassure them that no agent had ever been asked about them by their German spymasters. Recalling it all twenty years afterwards, Eisenhower chuckled and said ‘By God, we fooled them, didn’t we?’
Ben Macintyre's new book Double Cross: The true story of the D-Day spies is available from Bletchley Park Shop - £16.99 plus £3.00 UK post and packing. Please call 01908 272684 to purchase.