Seventy years ago to the day Allied troops embarked on one of the most audacious and daring military operations of all time.
Some 150,000 people packed on to landing craft, backed by the navy and air force.
What followed was a brutal, bloody, costly but ultimately successful invasion of occupied France.
It marked the beginning of the end for Hitler and the Third Reich.
The codename was Operation Overlord. We now know it as D-Day.
Planning began back in 1943, when Allied generals spotted an opportunity to turn the tide of the war in their favour.
Americans and Canadians were shipped over in their thousands and put up in huge camps along the south coast of England.
Secret meetings were held, with Winston Churchill heavily involved, and four invasion sites were considered: Brittany, the Cotentin Peninsula, Normandy and Calais.
The Germans were expecting us and had their eye firmly fixed on Calais, with it providing the shortest crossing.
But five beaches in Normandy were eventually chosen.
Omaha and Utah would be taken by the Americans. The Canadians would take care of Juno and the Brits Gold and Sword.
The lack of available harbour in Normandy threatened to scupper the whole operation but one of the most intuitive and genius inventions in history sorted the issue.
Although the brain behind the Mulberry Harbour is disputed, Hugh Iorys Hughes, a Welsh civil engineer, along with the scientist John Desmond Bernal and naval commander of the disastrous Dieppe raid John Hughes-Hallett are all credited.
The artificial harbour was pre-built in Britain before being carefully towed across the English Channel at no more than 5mph.
Remarkably almost the entire 600,000-ton structure made it safely and the 33 jetties and 10 miles of floating roadways were constructed at Omaha beach and Arromanches.
It provided a vital landing point and place for supplies to ensure the invasion could continue.
However, not all the harbour made it over safely. A section of the Mullbery sank on the way just off of Pagham. It remains underwater and is now a popular site for divers.
Everything was in place and the tens of thousands of Allied troops stood in their landing crafts in the middle of the Channel waiting for the signal.
Just after midnight on June 6, bombardment of the German defences began.
Meanwhile paratroopers were being dropped in behind enemy lines to secure key towns, bridges and roads.
One of the most daring attacks during D-Day was also one of the first. Six gliders, packed with British infantry, flew in at low level over Northern France before dropping in just metres from one of the key strategic targets, Pegasus Bridge.
They took the garrison by surprise and within minutes had secured the route over the Caen Canal.
It was later described as one of the most “outstanding flying achievements of the war”.
Shortly after 6am the signal was given and the first of the landing craft were sent off towards the five beaches.
The first ramp dropped at Utah at 6.30am.
American troops poured on to the sands, dodging machine gun and sniper fire while trying to find cover before the tank traps and dunes.
Shortly after, the Americans landed at Omaha. Enemy fire rained down on them from the heavily fortified defences with hundreds gunned down before they reached the sand.
A fierce six hours of fighting ensued but by noon the Germans were running out of ammunition. The Americans took their chance and stormed the cliff tops before finally taking control of the beach.
The Canadians also suffered heavy losses at Juno with mines and heavy machine gun fire killing nearly a thousand.
Sword beach’s mines and tank traps led to heavy casualties with more than 1,000 dead or missing while those landing at Gold continued their fierce fighting into the nearby French town.
More than 4,000 allied troops were dead by the end of D-Day with at least 12,000 casualties.
The Germans had lost just 1,000.
But with the sun setting on June 6 1944, the Allies had a foothold in Nazi-occupied Europe for the first time since the war began.
For Hitler and the Third Reich it was the beginning of the end.
For the Allied forces, it was their longest day.