More than 38,000 people have taken part in the London Marathon, making it the biggest in the event's 35-year history.
Fund raisers, amateur runners and elite athletes tackled the 26.2 mile (42.2km) course from Blackheath to The Mall.
Paula Radcliffe, 41, a former winner and the current world record holder, ran her final marathon.
She said: "I didn't care about the time the whole way round. I was so tired. I wanted to try and thank as many people as possible."
She started with the mass starters rather than the elite field for her final run along the course, on which she set the world record of two hours, 15 minutes and 25 seconds in April 2003.
In her final race, Radcliffe finished in an unofficial time of two hours, 36 minutes and 55 seconds.
Three-time winner Radcliffe, who has had to nurse an Achilles problem just to make it to London, was honoured with the inaugural John Disley Lifetime Achievement award at The Mall finish.
Organisers said the number of competitors this year surpassed the previous record of 37,227 in 2012.
Many competitors were raising money for charity and hoping to beat the 2014 record amount of £53.2m.
Home favourite David Weir, who was hoping to land a record seventh crown, finished second behind American Joshua George in the men's wheelchair race, while Tatyana McFadden claimed her third straight title in the women's wheelchair race.
Ethiopia's Tigist Tufa won her first London Marathon title in the women's race, and in the men's race Kenya's Eliud Kipchoge finished first.
Many celebrities ran the race, including Formula 1 star Jenson Button and Radio 1 DJ Greg James.
Some runners like Rob Young gave themselves additional challenges.
It was his 367th marathon in a year, having ran at least one marathon a day since watching last year's event.
The mother of the cancer fundraiser Stephen Sutton also ran her first London Marathon to keep a promise she made to her son before he died.
Jane Sutton said: "When I have been going out running he has been the person I am thinking about and hopefully I've got the same determination as him so I will cross that finish line."
Laura Harvey and Paul Elliott started married life on the run by tying the knot halfway through the race.
Speaking before the race, Ms Harvey said: "We're both running separately halfway. We run to about Tower Bridge, come off go to our venue, have a quick change to warm up, get married, have a few photos and then go to the end."
The oldest entrant was Paul Freedman, 90, from Hornchurch, Essex, while the youngest was Jonny Innes from Falmouth, Cornwall, who was celebrating his 18th birthday.