Britain's Queen Elizabeth II along with around one million members of the public are set to attend ceremonies to remember the 1944 Allied landings, which hastened the defeat of Nazi Germany.
An international ceremony of remembrance on the beach at Ouistreham in Normandy is expected to include some 1,800 veterans.
On Thursday the spotlight was firmly on those who risked their lives in launching the invasion, the largest sea assault in military history, to liberate Europe from Nazism.
Most of those WWII combatants are now in their 90s and were marking the occasion in France for probably the last time.
One of them, Jock Hutton, celebrated in a unique way by parachuting to the same spot he landed on as an 19-year-old, this time with a member of the Red Devils strapped to his back for safety.
Wearing a bright red jumpsuit, the 89-year-old veteran touched down lightly on the grass just in front of the waiting Prince Charles, dusted himself down briskly and removed his helmet.
"I was hoping there'd be some Calvados," he quipped on arrival.
"At my age, life tends to get a wee bit boring. So you've got to grab at any chance at excitement," he said.
As colonel-in-chief of the Parachute Regiment, Prince Charles, the heir to the British throne, led the tributes to those in the first wave of air landings shortly after midnight on June 6.
Wearing a field marshal's uniform, he chatted at length to veterans, many of whom were confined to wheelchairs, along with his wife Camilla.
The royal couple then hopped into a motor gunboat, one of the lead boats on the approach to Swords Beach on the historic day seven decades ago.
"Did you jump here?" the prince asked paratrooper Raymond Shuck. "And in the right place?" he joked, in reference to the fact that several parachutists landed in completely the wrong place in the darkness and confusion of the assault.
Queen Elizabeth, who has cut back her engagements recently due to her advancing years, received a warm welcome from hundreds of well-wishers as she alighted at the Gare du Nord in Paris on Thursday in a cream-white coat and matching hat on Thursday.
After a quick change into a pink outfit, she took part in a ceremony at the eternal flame at the Arc de Triomphe which marks the grave of the unknown soldier, before taking tea with Hollande at the Elysee Palace.
- Putin returns to international stage -
Putin returned to the international centre stage on Thursday, holding his first meetings with Western leaders since the eruption of the Ukraine crisis.
The Russian leader, who has been cold-shouldered by the United States and its allies since the March annexation of Crimea, met both British Prime Minister David Cameron and then French President Francois Hollande on a night of gastro-diplomacy in Paris on Thursday.
On the sidelines of Friday's ceremonials, German Chancellor Angela Merkel is due to have her own tete-a-tete with Putin in the morning.
- 'Jumping blind' -
World War II veteran, Ernest "Ernie" Stringer, attending Thursday's events, spoke of his terror as he piled out of a low-flying military aircraft in pitch darkness 70 years ago.
"I was dead scared. You don't know what's going to happen to you. You are jumping blind. You don't know where the Germans are," Stringer, also 19 at the time, told AFP.
"As it happened we were virtually surrounded but we didn't know that. And they didn't know we were there either!" he added.
Many of those who jumped before him were not so lucky. The man ahead of Stringer hit a wall and broke his arm. Several died on impact, with no time to open their chutes as the planes were flying so low.
More than 156,000 troops waded or parachuted onto French soil on June 6, 1944. Nearly 4,500 would be dead by the end of the day.
US, French and Dutch soldiers took part at an evening ceremony at Utah beach, on the western edge of the invasion site and a huge firework display lit up the Normandy coastline to mark the first bombing raids.
Stringer said he had been several times to events marking D-Day but his circle of contemporaries was shrinking fast.
"You keep looking for your friends. Always wondering who's missing, because there's so few left."
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