Tens of thousands of runners set off in good conditions as the London Marathon got under way today.
Up to 36,500 athletes are expected to finish the 26.2-mile course after pounding through the streets of the capital to earn their marathon medals and raise money for countless charities.
As well as the elite athletes and fun runners, a host of celebrities crossed the start line in support of good causes.
Glamour model Nell McAndrew is an experienced marathon runner for Cancer Research UK with a personal best of three hours and ten minutes.
"It's just such an incredible day. I feel really lucky to have a place to experience the London Marathon again," she told the BBC.
Olympic rowing champion James Cracknell suffered serious brain damage when he was hit by a truck in a cycling endurance race in America last July.
He said competing in the marathon for brain injury charity Headway was an opportunity to look to the future.
"Today I can draw a whole line under the thing and move on," he said.
His former team-mate Matthew Pinsent, who is raising money for Alzheimer's Society, said he wanted to beat his previous time of four hours and eight minutes.
He said: "That eight minutes has been annoying me. I'm going to have that in my mind as I go around the Docklands today. I just need to get under four (hours), that's my target."
Comedian Joe Pasquale is running for Diabetes UK as several of his close family members have been affected by the disease, including his daughter.
He said he did not have a finish time in mind, and joked that he had "Vaseline in places I can't tell you".
Meanwhile British 400m record holder Iwan Thomas revealed he will treat himself to a new motorbike if he achieves his target time.
"I promised myself if I go under four hours I'm going to buy myself a Harley-Davidson tomorrow morning. So four hours is the target, but I think I can do it if I run smart."
Conditions at the start in Blackheath were overcast and dry, with the temperature at 9C (48F). But forecasters expected that would rise to as high as 19C (66F) by mid-afternoon as the fun-runners complete the course at Buckingham Palace.
Kenyan Emmanuel Mutai set a new course record in winning the men's race with a time of two hours, four minutes and 40 seconds.
He beat the previous best by 30 seconds.
Three-time winner Martin Lel and Patrick Makau made it a clean sweep for Kenya, Lel just edging out his compatriot in a sprint finish.
It was an incredibly successful day for competitors from the east African country, as Mary Keitany claimed a commanding victory in the women's race, clocking a time of two hours 19 minutes and 19 seconds.
She relegated defending champion Liliya Shobukhova of Russia into second, with Kenya's Edna Kiplagat in third.
Britain's Jo Pavey enjoyed an excellent marathon debut, finishing 19th in 2:28.23.
In the wheelchair race home favourite David Weir claimed an unprecedented fifth title with a perfectly timed sprint finish.
Weir waited until he was within sight of the finish on The Mall before powering past Switzerland's Heinz Frei to become the most successful wheelchair athlete in the event's history.
In the women's race, Shelly Woods came within centimetres of making it a British double when she was pipped on the line by American Amanda McGrory.