The Queen led a two-minute silence at Westminster Abbey
The horrors and heroism in the trenches of World War I have been remembered in a series of Armistice Day services.
At Westminster Abbey the Queen and prime minister marked "the passing of a generation" with a two-minute silence.
While in Afghanistan, serving British soldiers commemorated the day at UK military bases in Helmand province.
The ceremonies follow the deaths this year of the final three WWI veterans living in Britain - Bill Stone, Henry Allingham and Harry Patch.
Mr Allingham's nephew, who was at the abbey service in London, described it as a "poignant tribute for all the WWI veterans".
Ronald Cator, 75, said: "It was a great honour, for us and the whole family. It was very moving."
Mr Stone died at 108 in January followed by Mr Allingham, 113, and Harry Patch, 111, in July.
AT THE SCENE
Alex Kleiderman, BBC News
The congregation consists of a cross-section of people and generations.
There are the relatives of the three last veterans of WWI in the UK whose deaths inspired the event, and sons, daughters and grandchildren of other servicemen, including some of those who never returned. Some are wearing their relatives' war medals.
Schoolchildren, whose only connection to the Great War is from history books, are also in attendance.
A Union Flag that was draped on the bodies of the fallen during WWI is hanging over the Tomb of the Unknown Warrior, which symbolises all those who died in the war, and is a focal point for the service.
The Prince of Wales - who joined Canadians in honouring their war dead at a service in Ottawa - praised British people for the backing they have given troops returning from Afghanistan.
Prince Charles, who is colonel or colonel-in-chief of a number of regiments, said: "There was a time when my regiments in the UK were coming back to Britain and simply not being properly recognised or supported when they marched through the towns.
"Now, thank God, it's completely different and there is huge support," he told ITV's News at Ten.
Prince Edward had led the congregation at a service of remembrance at the Armed Forces Memorial near Lichfield in Staffordshire.
The Royal British Legion also held two events, in London's Trafalgar Square and Swansea's Castle Square, for people who wanted to observe the two-minute silence with others.
The public gathered at Edinburgh's Garden of Remembrance for the silence, marked by a gun from Edinburgh Castle, while Glasgow's Lord Provost led a remembrance service at the George Square war memorial.
In Wales, the parents of the 200th soldier to be killed in Afghanistan used the Armistice commemorations to announce they were setting up a foundation in his memory.
Richard Hunt, 21, who lived near Abergavenny in Monmouthshire, died in hospital in August, two days after an explosion in Helmand province.
Pte Hunt's parents Hazel and Philip plan to launch the Richard Hunt Foundation at the end of the month, to work with other charities to help and support injured Welsh soldiers and those who have served in Welsh regiments.
Representatives from every county with links to the war attended the Westminster Abbey service along with various members of the armed forces, government, ambassadors and high commissioners.
We hope that men like Henry... can be an inspiration to the troops currently putting their lives on the line
The president of St Dunstan's, a charity for blind and visually impaired ex-service personnel was also among the congregation.
Ray Hazan, 64, a former captain in the Royal Anglian Regiment, was blinded in 1973 by an IRA parcel bomb in Northern Ireland and became a friend of Mr Allingham's after his organisation started helping the centenarian in 2005.
He told the BBC: "He was a great inspiration, a great man for going around schools and telling them what it had been like in the hope that people didn't do that sort of the thing again."
Mr Hazan added: "We hope that men like Henry... can be an inspiration to the troops currently putting their lives on the line in Afghanistan."
Mr Patch, the last surviving Tommy, died aged 111 at his care home in Wells, Somerset, in July.
William Stone, originally from Watlington in Oxfordshire, was the last British serviceman to have seen active duty in both world wars. He died at a care home in Sindlesham near Wokingham, Berkshire, on 10 January.
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