World War II: Commencement of Operation Overlord: The Allied invasion of Normandy begins with the execution of Operation Neptune—commonly referred to as D-Day—the largest seaborne invasion in history. Nearly 160,000 Allied troops cross the English Channel with about 5,000 landing and assault craft, 289 escort vessels, and 277 minesweepers participating. By the end of the day, the Allies have landed on five invasion beaches and are pushing inland.

Operation Overlord was the codename for the Battle of Normandy, the Allied operation that launched the successful liberation of German-occupied Western Europe during World War II. The operation was launched on 6 June 1944 (D-Day) with the Normandy landings. A 1,200-plane airborne assault preceded an amphibious assault involving more than 5,000 vessels. Nearly 160,000 troops crossed the English Channel on 6 June, and more than two million Allied troops were in France by the end of August.