The Allied invasion of Europe during the summer of 1944 was widely expected and it fell to the Axis intelligence services to provide High Command with advance warning of the precise date and place of the landings.

Using cryptanalysis of Allied signals, undercover agents and ships, and photographic evidence, Axis intelligence was pitted directly against their Allied counterparts, who actively tried to create a decoy and aim their enemies at the wrong location.

The success of Operation Overlord has played a large part in historians usually disparaging the German army as incompetent and corrupt. However, recently declassified documents that allow a comprehensive assessment of the Axis intelligence collection effort suggest a different story.

Spies on the ground, codebreakers from across the Axis and photo intelligence: theirs was a sophisticated, integrated intelligence system that was supremely conscious of the Allies' counter-intelligence schemes.

Having learned of the significance of the OVERLORD codeword from a spy at the British embassy in Ankara in 1943, Berlin made the project a priority and dedicated resources to provide the High Command with a surprisingly accurate evaluation of the Allied order of battle and their invasion strategy.

For the first time, acclaimed intelligence author Nigel West provides the full, true story of Axis intelligence and how they affected the events of the D-Day landings.