D-Day: Planning Operation Overlord

Operation Overlord, the Allied invasion of Normandy on 6 June 1944, was the largest and most complex amphibious operation in military history. Its planning took over a year and involved deception operations, logistical feats, and coordination between nations on an unprecedented scale.

The deception campaign, Operation Fortitude, was designed to convince the Germans that the main invasion would target the Pas-de-Calais rather than Normandy. Fake armies with inflatable tanks, dummy radio traffic, and double agents fed false intelligence to German commanders. The deception was so effective that even after D-Day, Hitler kept reserves at Calais awaiting a second invasion that never came.

The logistics were staggering: 6,939 vessels, 11,590 aircraft, and 156,000 troops crossed the Channel on the first day. Two artificial harbours (Mulberry harbours) were towed across the Channel to support the supply chain. PLUTO (Pipe-Line Under The Ocean) pumped fuel directly from England to France.

The human cost was significant — over 10,000 Allied casualties on the first day alone. But the successful establishment of a beachhead in Normandy opened the second front that Stalin had demanded and began the liberation of Western Europe.