Photos: The Allied invasion of Normandy American troops storm the beaches of Normandy, France, on June 6, 1944. D-Day was the largest amphibious invasion in history. More than 160,000 Allied troops -- about half of them Americans -- invaded Western Europe, overwhelming German forces in an operation that proved to be a turning point in World War II. Hide Caption 1 of 15

Photos: The Allied invasion of Normandy U.S. troops wait to disembark a landing craft on D-Day. Hide Caption 2 of 15

Photos: The Allied invasion of Normandy American troops help their injured comrades after their landing craft was fired upon. Allied forces secured the beaches at a cost of about 10,000 casualties. Hide Caption 3 of 15

Photos: The Allied invasion of Normandy French commandos equipped with bicycles disembark from their landing craft after Allied forces stormed the Normandy beaches. Germans rained mortars and artillery down on Allied troops, killing many before they could even get out of their boats. Fighting was especially fierce at Omaha Beach, where Nazi fighters nearly wiped out the first wave of invading forces and left the survivors struggling for cover. Hide Caption 4 of 15

Photos: The Allied invasion of Normandy The British Army's 50th Infantry Division lands on beaches in Normandy. This photograph is part of an exhibit in London at the Imperial War Museum Hide Caption 5 of 15

Photos: The Allied invasion of Normandy An aerial view shows 32 intentionally sunk American merchant ships that served as a breakwater as well as anti-aircraft platforms. Hide Caption 6 of 15

Photos: The Allied invasion of Normandy Traffic builds up on the beach and on the road leading to Le Hamel, France, during the landing of the 50th Infantry Division. Hide Caption 7 of 15

Photos: The Allied invasion of Normandy U.S. troops and vehicles are ready to disembark. D-Day was one of history's most consequential and gut-wrenching battles. Hide Caption 8 of 15

Photos: The Allied invasion of Normandy A sign outside of Trinity Church in New York invites worshippers to pray for Allied victory in the D-Day invasion. Hide Caption 9 of 15

Photos: The Allied invasion of Normandy Commandos with the Royal Navy's 4th Special Service Brigade advance to Juno Beach at Saint-Aubin-sur-mer. Hide Caption 10 of 15

Photos: The Allied invasion of Normandy Lance Cpl. Walter Ray of the British Army shares a bottle of rum he found floating in the sea. Hide Caption 11 of 15

Photos: The Allied invasion of Normandy U.S. Gen. Dwight D. Eisenhower, left, supreme commander of the Allied forces, and British Field Marshal Bernard Montgomery, right, discuss plans at an undisclosed location in June 1944. The Allies went to elaborate lengths to maintain secrecy and mislead Adolf Hitler. They employed double agents and used decoy tanks and phony bases in England to hide actual troop movements. Hide Caption 12 of 15

Photos: The Allied invasion of Normandy Eisenhower gives the order of the day to paratroopers in England. "Full victory -- nothing else" was the command just before they boarded their planes to participate in the first wave. The invasion -- code-named Operation Overlord -- had been brewing for more than two years. Hide Caption 13 of 15

Photos: The Allied invasion of Normandy British troops pose for a photograph with a French woman in La Breche d'Hermanville. Hide Caption 14 of 15