Here is a look at what you need to know about D-Day . Allied troops invaded Normandy on June 6 , 1944 . Facts : June 6 , 1944 - D-Day , World War II , the Allied invasion of Normandy . The largest seaborne invasion in history . The invasion 's code name was Operation Overlord . General Dwight D. Eisenhower commanded the operation , and plans were made to land in Normandy , west of where the German troops and artillery are built up . More : See historic photos from the landing . The `` D '' stands for Day . D-Day and H-Hour stand for the secret time/day an operation is scheduled to begin . Code names for the five beaches where the Allies landed : Utah , Omaha , Gold , Juno , and Sword . The date June 5 , 1944 was originally chosen for the invasion , but bad weather forced the Allies to postpone one day . Timeline : August 19 , 1942 - A raid on the French port of Dieppe that resulted in heavy losses convinces D-Day planners to land on the beaches , so discussions and preparations for an Allied invasion across the English Channel begin . May 1943 - The Trident Conference , a British and American strategy meeting on the war . In Washington , DC , Winston Churchill , President Roosevelt and their military advisers discuss , among other things , crossing the English Channel . August 1943 - The Quadrant Conference , where the British and American military chiefs of staff outline Operation Overlord . November and December 1943 - The Sextant and Eureka Conferences , where the British and American military chiefs discuss the specifics of the assault on France . 1944 - The Germans expect an invasion along the north coast of France , but they do not know where . They build up their troops and artillery near Calais , where the English Channel is the narrowest . June 5 , 1944 - Between 11 pm and 3 am , 13,000 allied paratroopers and gliders carrying heavy equipment leave England to begin the invasion of France by air . In a broadcast message to the troops , delivered before they leave , Eisenhower says , `` The tide has turned ! The free men of the world are marching together to victory ... . We will accept nothing less than full victory ! '' June 6 , 1944 - Overnight , a military armada and more than 156,000 troops cross the English Channel . Minesweepers go ahead to clear the waters in preparation for the more than 2,300 landing crafts that will be carrying men , vehicles and supplies . Between midnight and 8 am , Allied forces of more than 11,000 aircraft , fly 14,674 sorties . 6:30 am - Troops begin coming ashore on a 60-mile front . More : Before and after D-Day : Color photos . In a broadcast to the people of occupied Europe , Eisenhower says , `` Although the initial assault may not have been in your own country , the hour of your liberation is approaching . '' More about World War II and veterans : . By the numbers : Veterans from U.S. wars . CNN Heroes : Making life easier for disabled veterans . A daughter faces demons of father 's war . WWII Marine 's diary found by sweetheart years later . Must-see sights for military buffs .
During World War II , Allied troops invaded Normandy on June 6 , 1944 . It was known as D-Day .