Some marched for grandfathers and great-grandfathers who were among the survivors to clamber from the trenches in the drizzle of that November day.

Others marched for great-uncles and great-great-uncles; a fallen generation never to become fathers and known only through sepia photographs and the names chiselled on local war memorials.

This was not a military parade. But as 10,000 people, who were chosen by ballot, gathered for the people’s procession at the Cenotaph in London, family medals adorned chests, glinting in autumnal sunshine. They carried wreaths and photographs and thoughts of Laurence Binyon’s immortal words: “We will remember them.”

Described as “a nation’s thank you”, this was the chance for descendants to pay tribute to family members, now gone, at the national memorial. It was important, said Kate Nicholls, “because the generation who had first-hand knowledge are dying out, not just those who served, but those they told”.

Nicholls, from Ealing, west London, was walking for her great-grandfather, John Waugh, who was 28 when he was killed in action, two weeks before armistice, “which makes it seem doubly senseless,” she said. His older brother, Tommy, survived, despite being left for dead at the Somme, and hiding under dead bodies in no man’s land for three days to stay alive. Remarkably, just before John was killed, the brothers were briefly reunited at a field clinic in Flanders where their sister, Violet, was a nurse.

Jackie Sheridan, from Syston near Leicester, in her Scout-leader uniform, saluted as the procession passed the Cenotaph. “Then I looked down, and saw all the wreaths, and it really brought it home to me. I welled up. It was very emotional,” she said. She was attending with her husband, Steven, to remember her great-great-uncle, Oliver Davies, of the Royal Engineers, who died in Palestine aged 21, on 2 December 1917, when he was hit by a stray bullet.

Kate Nicholls, walking for her great-grandfather, John Waugh, was killed in action in Flanders in 1918. Photograph: Kate Nicholls

She has the letter, now fragile, which was sent to the family by his captain. He informed them of the mortal wounds and the fact he had made a cross for Davies’s grave. She has a photograph of a sketch of that cross on her phone.

“It’s important to show your respect,” she said, “I have a grandson who is only nine months old and I hope when he is old enough we will still carry on.”

The procession had mustered on the Mall, where giant screens relayed the nation’s wreath-laying ceremony in Whitehall, just yards away across Horse Guards Parade. As the chimes of Big Ben signalled the 100th anniversary of the 11th hour of the 11th day of the 11th month, heads bowed as many remembered stories told by long-departed loved ones who had lived the full horror of the first world war. Loud cannon fire ended the two-minute silence. Over loudspeakers, strains of The Last Post played by Royal Marine buglers filled the still air.

At 12.30pm, as Big Ben struck once more to signal the pealing of bells across the country, and across the world, the procession set off.

For Julia Knowles, the day had begun at 6am, with a pipers’ lament in howling rain in her village of Chaldon, Surrey. Now, in sunshine, she and her husband, Bob, were paying tribute to her grandfather, Arthur Hines. He survived the war, and went on to marry a young French woman he met in Lille. But all his life he kept a letter sent to him by the mother of a fallen comrade, thanking him for taking the trouble to write to her about her son.

“I thought it was really wonderful,” she said of the procession. “What really struck me was that absolutely everybody had their own story,” she said.

Leigh Todd with her husband, Richard. Photograph: Caroline Davies/The Guardian

Leigh Todd, from Scarborough, wanted to mark the life of her great-aunt, Nancy Allen, whose fiance was killed. She never married or had children. “She never stopped wearing black, and she kept the letters he wrote to her in a chocolate tin,” she said. She was one of countless women robbed of the future they had hoped for.

At the Cenotaph, the 10,000 walked slowly passed, just as 1 million had done so before them when it was first hastily erected from wood and plaster to commemorate the “Great Deliverance” from the unimaginable agony of what was supposed to be the war to end all wars. The memorial designed by Edwin Lutyens in Portland stone, which replaced that first cenotaph in 1920, has had a busy history since it first became the focal point for commemorations.

The last veterans from the first world war are gone. Those from the second world war are fading. Perhaps, many of those gathered hoped, a people’s procession could become part of the nation’s annual commemoration.

Clutching a frame, inside of which he had mounted his father’s war medals and a photograph of his father, Derek Gregory hoped it would not be the last. “I think they should do it every year,” said the 88-year-old from Sidmouth, Devon. “It would be unforgivable if it all just faded away.”

His father, Albert James Gregory, of the South Wales Borderers, had been gassed, but survived. His medals almost didn’t. Albert, who suffered health problems as a result of of his experiences in the war, threw them in the coal hole in disgust at the lack of welfare assistance offered to veterans after the first world war. His wife later managed to retrieve two, both of which were carried past the Cenotaph by his son in this unique commemoration.