Normandy Invasion, also called Operation Overlord or D-Day, during World War II, the Allied invasion of western Europe, which was launched on June 6, 1944 (the most celebrated D-Day of the war), with the simultaneous landing of U.S., British, and Canadian forces on five separate beachheads in Normandy, France. By the end of August 1944 all of northern France was liberated, and the invading forces reorganized for the drive into Germany, where they would eventually meet with Soviet forces advancing from the east to bring an end to the Nazi Reich.In midsummer 1943, a year before the Anglo-American invasion of Normandy that would lead to the liberation of western Europe, Adolf Hitler’s Wehrmacht (“Armed Forces”) still occupied all the territory it had gained in the blitzkrieg campaigns of 1939–41 and most of its Russian conquests of 1941–42. It also retained its foothold on the coast of North Africa, acquired when it had gone to the aid of its Italian ally in 1941. The Russian counteroffensives at the Battle of Stalingrad and the Battle of Kursk had pushed back the perimeter of Hitler’s Europe in the east. Yet he or his allies still controlled the whole of mainland Europe, except for neutral Spain, Portugal, Switzerland, and Sweden. The Nazi war economy, though overshadowed by the growing power of America’s, outmatched both that of Britain and that of the Soviet Union except in the key areas of tank and aircraft production. Without direct intervention by the western Allies on the Continent—an intervention that would centre on the commitment of a large American army—Hitler could count on prolonging his military dominance for years to come.
Since 1942, Soviet leader Joseph Stalin had been pressing his allies, U.S. President Franklin D. Roosevelt and British Prime Minister Winston Churchill, to mount a second front in the west. It was impossible in the circumstances. America’s army was still forming, while the landing craft necessary to bring such an army across the English Channel had not yet been built. Nevertheless, Britain had begun to prepare theoretical plans for a return to the continental mainland soon after the retreat from Dunkirk, France, in 1940, and the Americans, immediately after Hitler declared war on the United States on December 11, 1941, had started to frame their own timetable. Less inhibited than the British by perceived technical difficulties, the Americans pressed from the start for an early invasion—desirably in 1943, perhaps even in 1942. To that end George C. Marshall, Roosevelt’s chief of staff, appointed a protégé, Dwight D. Eisenhower, to the U.S. Army’s war plans division in December 1941 and commissioned him to design an operational scheme for Allied victory.
