Operation Overlord was the code name for the Allied invasion of Normandy on D-Day in June 1944. Over 156,000 troops crossed the English Channel in the largest seaborne invasion in history. Through massive air attacks, naval bombardments, and amphibious landings along the Normandy coast, the Allies were able to establish a foothold in France and begin defeating German forces, marking a turning point in World War 2. The invasion involved troops and equipment from the United States, United Kingdom, Canada and other Allied nations crossing the channel and storming the beaches with weapons such as the M1 Grand rifle and Thompson submachine gun.