At the end of the war, Allied Intelligence Officers discovered
in captured files of the German Secret Service the text of two
hundred and fifty messages received from agents and other
sources before D-Day. Nearly all mentioned July and the
Calais sector. One message alone gave the exact date and
place of the invasion. It had come from a French colonel in
Algiers. The Allies had discovered this officer was working
for the Abwehr, and he was arrested and subsequently turned
round. He too was used to mislead Berlin—used and abused.
The Germans were so often deceived by him that they ended
by treating all his information as valueless. But they kept in
contact, for it is always useful to know what the enemy wants
you to believe. Allied Intelligence, with great boldness and
truly remarkable perversity, had the colonel announce that the
Invasion would take place on the coast of Normandy on the
5th, 6th or 7th June. For the Germans, his message was
absolute proof that the invasion was to be on any day except
the 5th, 6th or 7th June, and on any part of the coast except
Normandy.