With the Allied advance in Italy largely stalled in late 1943, and Soviet leader Joseph Stalin still clamoring for a second front in the West, planning began for the long anticipated invasion of occupied France. General Dwight D. Eisenhower was recalled from the Mediterranean to England, where the newly appointed Supreme Allied Commander presided over the most ambitious undertaking of the war, codenamed Overlord. The buildup continued for months as troops, tanks, aircraft, heavy guns, and myriad other equipment and supplies were stockpiled across Britain.

The invasion was set for early June 1944, when tidal conditions and moonlight would be optimal. In the early morning darkness, hours before dawn, 23,000 American and British paratroopers and glider-borne infantry would land behind enemy lines throughout the coastal province of Normandy. Their mission was to seize inland roads, bridges, and causeways, blocking German reinforcements and counterattacks. At daybreak, a massive naval barrage and aerial bombardment would soften up the German beach defenses for the first waves of assault troops. Divisions from the US First Army would land on beaches designated Utah and Omaha, then drive toward the Cotentin Peninsula and the deep water port at Cherbourg. Elements of the British Second Army would land on Gold, Sword, and Juno Beaches before converging on the city of Caen – a key gateway on the road to Paris.

The operation began on June 6, 1944, in rainy and overcast conditions. Though heavy cloud cover and antiaircraft fire disrupted many of the airborne drops, leaving American paratroopers scattered across Normandy, most of the seaborne troops fared better, meeting only light resistance on the beaches. The exception was Omaha Beach, which quickly erupted into a firestorm of horrors for the Americans. It was the most heavily defended sector, and as the first waves of troops came ashore, they were riddled by German machine-gun fire from atop high bluffs overlooking the beaches. The guns were eventually silenced, but more than 2,000 Americans were killed or wounded that morning on Omaha Beach, accounting for nearly half of all Allied casualties on D-Day.

By afternoon, a tenuous foothold had been secured in Normandy, and as additional men and equipment poured onto French soil, British, American, and Canadian forces began battling toward their early objectives.