Amid the commemorations, here are five facts about Operation Overlord:
It was the largest air, land and sea operation in military history
The landings featured the combined forces of 13 different countries - including Greece, Rhodesia, New Zealand and Norway. Almost 7,000 naval vessels were tasked with transporting the 132,000 ground troops across the English Channel to the five beaches chosen for the landings. At the same time 18,000 paratroopers were dropping into the invasion zone and the Allied air forces flew 14,000 sorties to bombard the German positions in Normandy.
Its success relied on subterfuge and misdirection
In the run up to the invasion a great deal of effort was put into convincing the German forces that the invasion would take place miles from the actual target. An entire fake US division was created in south-east England, using inflatable tanks and dummy landing craft to draw German attention. Double agents passed false information to confuse the German force. And in one famous incident - Operation Mincemeat - the body of a tramp was disguised as a dead RAF officer and was dumped off the coast of Spain with false invasion plans in his pocket. It all led to the Germans holding back forces from Normandy in expectation of an attack closer to Calais, weakening their defence to the actual landings.
D-Day was only the beginning
While the success of the D-Day landings was massively significant, it was only the beginning of the battle to liberate France from German occupation. By securing a beachhead for Allied troops to land it meant they could push in to France and take on the German army on the ground. It was not easy going, however, and there were many more bloody battles before British and American troops crossed into Germany itself in early 1945.
Casualty rates varied widely
While the numbers of killed and wounded troops was actually lower than the Allied commanders had feared, the landings were still a bloody affair. In particular, the American troops landing at Omaha beach suffered very high casualty rates. The figures are debated but it is thought that at least 2,000 US soldiers were wounded or killed at Omaha on June 6. In total it is thought that around 4,000 Allied troops lost their lives that day, with thousands more wounded.
Star Trek’s Scotty was among the invasion force
Among the 14,000 Canadian soldiers who helped make up the invasion force was Lieutenant James Doohan. Doohan was shot six times - in the leg, chest and hand - but survived, in part, thanks to a cigarette case which deflected the bullet that hit his chest. He didn’t escape unscathed however, losing a finger on his right hand. After the war Doohan went into acting, eventually landing the role of Chief Engineer Montgomery “Scotty” Scott in Star Trek.