On June 6, 1944, >5,000 Allied ships, supported by 13,000 airplanes performed the largest amphibious landing in the history of warfare. Code-named Operation Overlord, the invasion of ~50 miles of beach in Normandy France signaled the beginning of the tough campaign to liberate Nazi-occupied Europe.
By August 1944, northern France was liberated; in June 1945 Nazi Germany surrendered.
The losses on both sides were staggering: 216,000 German and 209,000 Allied troops were killed, wounded or missing during the Battle of Normandy with an additional 16,714 deaths of Allied airmen.
WARNING: this clip from the film Saving Private Ryan is a gruesome, vivid depiction of the landing on Omaha Beach.