The Queen has led the tributes to those who took part in D-Day 75 years ago in a major celebration bringing together world leaders including Donald Trump and Angela Merkel in Portsmouth.
D-Day, which unfolded in the early hours of 6 June 1944, was the largest seaborne invasion in history and was a major turning point in World War Two.
Veterans were applauded by the world's leaders as they stood on a large stage beside a guard of honour as a film montage with footage from the invasion played behind them.
In a moving speech, the Queen, who trained as a truck mechanic during the War, said: "The wartime generation - my generation - is resilient, and I am delighted to be with you in Portsmouth today.
"The heroism, courage and sacrifice of those who lost their lives will never be forgotten. It is with humility and pleasure, on behalf of the entire country – indeed the whole free world – that I say to you all: thank you."
The commemorations were taking place on the last day of US President Donald Trump's state visit to Britain.
During the event, he read a prayer given by Franklin D Roosevelt in 1944: "The enemy is strong. He may hurl back our forces but we shall return again and again; and we know that by Thy grace, and by the righteousness of our cause, our sons will triumph."
Other leaders in attendance included Prince Charles, Theresa May, French President Emmanuel Macron, Canadian Prime Minister Justin Trudeau, and Australian Prime Minister Scott Morrison.
D-Day is remembered as the starting point of the liberation of Europe from Nazi occupation. Under the command of US General Dwight D Eisenhower, over 150,000 mostly American, British and Canadian troops assaulted 50 miles of the Normandy coast by land, sea and air.
Some of those who waded to shore under German gunfire were only teenagers. The dead on both sides amounted to thousands and survivors later told of how the sea turned red.
"I was terrified. I think everyone was," said John Jenkins, 99, a veteran who landed at Gold Beach, told Reuters. "You never forget your comrades because we were all in it together."
On Wednesday evening, around 300 veterans were to retrace the journey they made across the English Channel 75 years ago on the specially commissioned ship, MV Boudicca, accompanied by Royal Navy vessels and a wartime Spitfire fighter plane.
Commemorations, including services of remembrance and thanksgiving, are to continue in the UK throughout the week. Special events will also be held in France on Thursday, including a reenactment of parts of the invasion.