On 6 June 1944 the Western Allies landed in northern France, opening the long-awaited "Second Front" against Adolf Hitler's Germany. Though they had been fighting in mainland Italy for some nine months, the Normandy invasion was in a strategically more important region, setting the stage to drive the Germans from France and ultimately destroy the National Socialist regime.

It had been four long years since France had been overrun and the British compelled to leave continental Europe, three since Hitler had attacked the Soviet Union and two and a half since the United States had formally entered the struggle. After an often seemingly hopeless fight, beginning in late 1942 the Germans had been stopped and forced into slow retreat in eastern Europe, defeated in North Africa and confronted in Italy. U.S. and British bombers had visited ruin on the enemy's industrial cities. Allied navies had contained the German submarine threat, making possible an immense buildup of ground, sea and air power in the British Isles.

Schemes for a return to France, long in preparation, were now feasible. Detailed operation plans were in hand. Troops were well-trained, vast numbers of ships accumulated, and local German forces battered from the air. Clever deceptions had confused the enemy about just when, and especially where, the blow would fall.

Commanded by U.S. Army General Dwight D. Eisenhower, the Normandy assault phase, code-named "Neptune" (the entire operation was "Overlord"), was launched when weather reports predicted satisfactory conditions on 6 June. Hundreds of amphibious ships and craft, supported by combatant warships, crossed the English Channel behind dozens of minesweepers. They arrived off the beaches before dawn. Three divisions of paratroopers (two American, one British) had already been dropped inland. Following a brief bombardment by ships' guns, Soldiers of six divisions (three American, two British and one Canadian) stormed ashore in five main landing areas, named "Utah", "Omaha", "Gold", "Juno" and "Sword". After hard fighting, especially on "Omaha" Beach, by day's end a foothold was well established.

As German counterattacks were thwarted, the Allies poured men and materiel into France. By late July these reinforcements, and constant combat, made possible a break out from the Normandy perimeter. Another landing, in southern France in August, facilitated that nation's liberation. With the Soviets advancing from the east, Hitler's armies were shoved, sometimes haltingly and always bloodily, back toward their homeland. The Second World War had entered its climactic phase.