The Invasion of Normandy was the invasion and establishment of Allied forces in Normandy, France during Operation Overlord in World War II. It covers from the initial landings on June 6, 1944 until the Allied breakout in mid-July.

It was the largest seaborne invasion at the time, involving over 850,000 troops crossing the English Channel from the United Kingdom to Normandy by the end of June 1944.

Allied land forces that saw combat in Normandy on June 6 came from Canada, Free French Forces, the United Kingdom, and the United States. In the weeks following the invasion, Polish forces also participated and there were also 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, 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, an early morning amphibious landing 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.
 http://en.wikipedia.org/wiki/Battle_of_Normandy