What was the secret name of the officers that were aware of the arrangements for d - day intrusion of Normandy ?
The book takes its name from a comment made by Erwin Rommel to his aide Hauptmann Helmuth Lang on 22 April 1944 : " ... the first 24 hours of the invasion will be decisive ... the fate of Germany depends on the outcome ... for the Allies , as well as Germany , it will be the longest day .