Winston Churchill said that the truth is so important that it must be accompanied by a bodyguard of lies. The truth of Operation OVERLORD - the Normandy Invasion of 1944 - was a truth of such magnitude that it was accompanied by the most extensive and complicated deception operations ever attempted in warfare. These efforts were so secret that many of them were only declassified in the late 1980s, meaning that our understanding of what happened, why, and how on that "Longest Day" was incomplete before them, at best.