Commemorations for the 75th anniversary of the D-Day landings take place this week. The Queen, US President Donald Trump and other heads of state are all due to attend.
So, what were the events that took place in June 1944?
What was D-Day?
Troops from the UK, the US, Canada, and France attacked German forces on the coast of northern France, on 6 June 1944.
It was the largest military operation ever attempted and marked the start of the campaign to liberate Nazi-occupied north-west Europe.
D-Day involved the simultaneous landing of tens of thousands of troops on five separate beaches in Normandy.
More than a year in the planning, D-Day was originally set to start on 5 June, judged to be the most likely date to combine calm seas, a full moon and low water at first light. However, storms meant it was delayed by 24 hours to 6 June.
D-Day is a military term for the first day of an operation.
What happened on the day?
Airborne troops were dropped behind enemy lines in the early hours, while thousands of ships gathered off the Normandy coast for the main attack.
Though they were expecting an invasion, German military leaders believed the initial attacks were only a diversionary tactic.
A deception plan in the weeks ahead of the attack had led them to expect the main invasion further along the coast.
The surprise element helped British troops establish a foothold on a beach codenamed Gold.
In addition, Canadian forces established themselves on another beach - Juno - and the British got on to Sword beach.
American soldiers also managed to land on the westernmost beach - Utah - without major casualties.
But at nearby Omaha beach, the US force suffered serious losses. The naval barrage and bombing raids on the German defences were ineffective and the Americans encountered a crack division of German troops.