The Normandy invasion aimed to establish the Allied armies in German-occupied Europe. Operation Overlord, as it was called, was the largest amphibious operation in history. The initial landing was on 6 June 1944 and after hard fighting, the Allied breakout occurred in late July.
Allied land forces that saw combat in Normandy on 6 June came from Canada, the Free French Forces, the United Kingdom, and the United States. In the weeks following the invasion, Polish forces also participated, as well as contingents from Belgium, Czechoslovakia, Greece, and the Netherlands. Most of the above countries also provided air and naval support, as did the Royal Australian Air Force, the Royal New Zealand Air Force, and the Royal Norwegian Navy.
The Normandy invasion began with overnight parachute and glider landings, massive air attacks, naval bombardments, early morning amphibious landings on five beaches codenamed Juno, Gold, Omaha, Utah, and Sword and during the evening the remaining elements of the parachute divisions landed. The "D-Day" forces deployed from bases along the south coast of England, the most important of these being Portsmouth.