June 6, 1944 is better known as D-Day, the day on which the Invasion of Normandy began as U.S., British, and Canadian forces set out to liberate Europe from Nazi control. It was the largest air, land, and sea operation ever undertaken, involving more than 5,000 ships, 11,000 airplanes, and 150,000 soldiers. When the dust cleared, Allied Forces had suffered almost 10,000 casualties but the German lines had been breached and the defeat of Hitler was in sight. The success of D-Day was absolutely essential to Allied victory in World War II.