First United States Army Group was a fictitious Allied Army Group in World War II prior to D-Day, part of Operation Quicksilver, created to deceive the Germans about where the Allies would land in France. To attract Axis attention, prominent US general George S. Patton was placed in command of the fabricated formation.

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.