The Normandy landings (codenamed Operation Neptune) were the landing operations on 6 June 1944 (termed D-Day) of the Allied invasion of Normandy in Operation Overlord during World War II. The largest seaborne invasion in history, the operation began the liberation of German-occupied northwestern Europe from Nazi control, and contributed to the Allied victory on the Western Front.
Planning for the operation began in 1943. In the months leading up to the invasion, the Allies conducted a substantial military deception, codenamed Operation Bodyguard, to mislead the Germans as to the date and location of the main Allied landings. The weather on D-Day was far from ideal, but postponing would have meant a delay of at least two weeks, as the invasion planners had requirements for the phase of the moon, the tides, and the time of day that meant only a few days in each month were deemed suitable. Hitler placed German Field Marshal Erwin Rommel in command of German forces and of developing fortifications along the Atlantic Wall in anticipation of an Allied invasion.