By 1944, Nazi Germany controlled most of Western Europe. To beat them, the Allies - mainly the United States, Britain and Canada - needed to land an army on the coast of France and fight their way inland. The plan was called Operation Overlord. The first day was code-named D-Day.
On June 6, 1944, around 156,000 Allied soldiers crossed the rough waters of the English Channel in over 5,000 ships, while more than 11,000 planes flew overhead. They landed on five beaches in Normandy, each given a code name: Utah, Omaha, Gold, Juno and Sword. Fighting on Omaha Beach was especially fierce.
A huge part of the plan was tricking the Germans. The Allies built fake army camps in eastern England complete with inflatable tanks, rubber trucks and fake radio chatter. Hitler was convinced the real invasion would land elsewhere - and held troops back. By nightfall on D-Day, the Allies had a foothold in France.