Organisers of the virtual London Marathon 2020 have said they are "delighted and incredibly proud" to have held the event during a worldwide pandemic.
With three hours to go, more than 25,000 people had completed the 26.2 mile race by following their own routes in locations across London and the country, while raising money for charities.
Runners in the UK were faced with lashing rain and gale-force winds, described by a veteran racer who has taken part in all 40 London marathons as the "worst ever" conditions.
Mencap, which supports people with learning disabilities, was Virgin Money London Marathon's Charity of the Year, and 312 runners including 10 with learning disabilities raised money for it through the event.
Aaron Plummer, who has cerebral palsy and a learning disability, completed the race in Walthamstow, London, to "give back to the greatest charity ever".
The 20-year-old secured his dream job in hospitality at Novotel with the help of Mencap's internship programme.
He was supported by celebrity trainer Joe Wicks, BBC DJ Joe Whiley and footballers including Arsenal's David Luiz while raising more than £23,000 through the race - which he completed in two halves over five hours and nine minutes.
The runner said he was looking forward to "watching the Arsenal game in the pub" at the finish line.
Mencap runner Tomas Cardillo-Zallo also completed the race, accompanied by a relay of relatives and the Countess of Wessex in Great Windsor Park, before running beside the River Thames to his home in Kingston-upon-Thames.
The Countess joined the 29-year-old runner, who has a learning disability and autism, for the first 1.5 miles to reflect the 1.5 million people with a learning disability in the UK.
Mr Cardillo-Zallo, who has taken part in over 100 park runs, said: "Thank you to Her Royal Highness for supporting me to run my first ever marathon.
"I loved every minute of it."
Mencap chief executive Edel Harris said people can still support the runners by donating to the charity's fundraising page.
She said: "Through your giving and encouragement, Mencap can continue to support people with a learning disability to lead happy and healthy lives, just like anyone else."
Some 45,000 runners from 109 countries across the world who registered for the first ever virtual London Marathon have until midnight on Sunday to finish their 26.2 miles and log it on the official app.
Hugh Brasher, event director of the Virgin Money London Marathon, said his team are proud to have "inspired" thousands of people to "take part in their own challenge" and "do it in their own way".
Mr Brasher said: "We are delighted and incredibly proud to have held this event during a worldwide pandemic.
"We wanted to give people a lift. The spirit of the London Marathon is about bringing people together.
"We couldn't get them together in reality, but we have brought them together as a community.
"The individual stories and achievements have been incredible, and we believe The 40th Race will live long in the memory. It truly has been a beacon of light in the darkness."
This year's finishers included 87-year-old Ken Jones, the oldest of the 10 "Ever Presents" who have completed every London Marathon to date, and Eileen Noble, the oldest woman in the virtual event at 85.
The veteran Ever Present said: "This year was the hardest because of the weather.
"We had heavy rain until the last three miles and we had to change our clothes three times because they were soaked through."
Mr Jones, who finished in seven hours and 53 minutes in Strabane, Northern Ireland, and plans to run again next year, said: "I'm very happy to finish. My neighbours had balloons out and signs up, we had a tremendous crowd really."
Mrs Noble ran her 20th London Marathon despite feeling "so cold" and having soaked feet after having to "paddle through water".
Running for Age UK, she said: "I thought I might look silly running along the river wearing my race number, but we passed lots of other runners - you'd have thought there was a real race on... it felt like the real thing in some ways."
The marathon's signature fancy dress runners included Anna Bassil, who ran around St Albans dressed as a giant birthday cake to raise money for Save the Children UK, and Peter Gillibrand, who ran in Cardiff dressed as a golden star to raise money for Mencap, who support his autistic brother.
Mr Gillibrand said he felt "pure emotion" finishing the virtual race on Sunday.
"Can't believe I managed to finish the 26.2 miles in a star for Mencap charity," he said.
"Thank you to everyone for support today. Loved spreading happiness even if it was the hardest thing I've ever done."
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