What was the largest naval, air and land operation in history?

D-Day states for the day on which a combat attack or operation is to be started. The initiation of the Battle of Normandy is the best known D-Day in the military history. On the 6th of June, 1944 the Allies of WWII (the countries fighting against the Axis powers) attempted to liberate mainland Europe from Nazi Germany.

More than 18 thousand Allied paratroopers, 14 thousand sorties, 7 thousand naval vessels and 132 thousand ground troops took part in the operation. It began with overnight parachute and glider landings, massive air attacks and naval bombardments. By the end of August the northern France was liberated from Germany. Later the invaders were reorganized and drove into Germany. They joined the efforts with the Soviet forces, which were coming from the east, and together brought an end to Hitler's Reich.