The King has led the nation in a two-minute silence during a Remembrance Sunday service at the Cenotaph.
He was joined by other members of the Royal Family and senior politicians, who laid wreaths to the fallen.
The Queen and the Princess of Wales took their places on one of the Foreign Office balconies overlooking Whitehall.
The Duke of Kent and the Duchess of Edinburgh were also on the balconies, along with the Duke and Duchess of Gloucester.
Three D-Day veterans were among those attending the ceremony.
In total, about 20 veterans who served in the Second World War were there, receiving applause as they took their positions close to the Cenotaph.
About a dozen people wearing military uniforms and poppies were pushed in wheelchairs.
Henry Rice, a former signalman who arrived off Juno Beach five days after D-Day, and Mervyn Kersh who arrived in Normandy aged 19, three days after the start of the D-Day invasion, were there.
Sid Machin, one of six 101-year-olds registered to march was also present and is one of the last surviving "Chindit" soldiers from the Second World War Burma campaign.
As a young man of about 19, Mr Machin landed behind enemy lines in a glider at night in the jungle, as part of a special forces unit in Burma (now Myanmar), which wreaked havoc on Japanese supply lines and infrastructure.
Donald Poole, 101, was a Royal Army Ordnance Corps technician who handled defective explosives or enemy ammunition.
He was serving in India in 1945 when the surrender of Japan was announced.
"It is a great honour to be able to pay tribute to the poor souls who have died in all conflicts and I know how lucky I am to still be here thanks to all those who have fought and served, past and present," he said.
"I also want to pay tribute to the civilian services who suffered during the Second World War, particularly the fire service, who saved so many lives during the Blitz, many of whom lost their own."
An estimated 10,000 armed forces veterans took part in the Royal British Legion's marchpast.
Prime Minister Sir Keir Starmer said: "This Remembrance Sunday, we pause as a nation to honour all those who have served our country.
"We reflect on the extraordinary courage of our Armed Forces in the world wars and subsequent conflicts, whose service secured the freedoms we cherish today."
Reflecting on the 80th anniversary of WWII, Sir Keir spoke of "a generation who stood against tyranny and shaped our future".
He added: "Such sacrifice deserves more than silence, which is why this government remains committed to supporting veterans, their families and those who serve.
"Today, we remember, and we renew our promise to uphold the values they fought for."
Chief of the Defence Staff Air Chief Marshal Sir Richard Knighton said: "From the Cenotaph in London to memorials in towns and villages across the United Kingdom, and wherever our Armed Forces serve around the world, we pause to remember their courage, their sacrifice and their enduring legacy.
"We shall remember them."
Last night, Sir Keir joined members of the Royal Family at the Royal British Legion's Festival of Remembrance.
Sir Rod Stewart, Sam Ryder and Keala Settle were on the bill, along with performances by the Central Band of the RAF, the RAF Squadronaires and the Band of HM Royal Marines during the event at London's Royal Albert Hall.
Ted Lasso star Hannah Waddingham hosted the festival and sang We'll Meet Again - telling the audience of the courage of her granddad, who is a veteran.
Harry Waddingham is 109, and one of the oldest living men in the United Kingdom.
The Princess of Wales was seen wearing a black dress adorned with a handmade poppy created out of silk, glass and other natural materials, along with earrings belonging to the late Queen.
The Prince of Wales was absent as he travelled back from Brazil where he attended the COP30 climate summit.
Prince George attended for the first time and watched intently as emotional videos of veterans speaking about their experiences were played.
The King was announced as a patron of the Royal British Legion last year.
(c) Sky News 2025: King leads nation in two-minute silence during Remembrance Sunday service at t

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