More than 40,000 runners took to the streets of the capital on Sunday to take part in the hottest London Marathon on record.
The Met Office recorded temperatures of 23.2C on Sunday for the 38th edition of the race.
Rain had initially been forecasted for the afternoon but the sun appeared to have no intention of going in.
Runners were advised to drop their goal-times and organisers added more ice, water and run-through shower stations along the 26.2-mile course.
Guidance was also issued to runners planning on running in fancy dress outfits, asking them to think carefully if this was still appropriate.
Every 2-3C rise in temperature above 15C can slow a runner’s pace by as much as 20 to 30 seconds per mile.
The Queen pressed a button at Windsor Castle to mark the start of the 26.2-mile race.
Among this year’s runners were firefighters who tackled the Grenfell Tower blaze, a police officer stabbed in the London Bridge terror attack and members of the Stephen Lawrence Charitable Trust. Sunday marks 25 years since the murder of the teenager, who was a keen runner.
Meanwhile almost 100 runners were attempting Guinness World Records – dressed variously in suits of armour, as mythical creatures, and wearing stilts and ski boots
Britain’s Mo Farah claimed third place in the men’s marathon, setting a new British record 2:06.22 - a record which had previously stood since 1985.
Kenya’s Eliud Kipchoge claimed his third London Marathon victory.
Britain’s David Weir, who won the men’s wheelchair race at the London Marathon for the eighth time, said: “The end was tougher than last year. Mentally and physically, I felt better coming into this.
“At the beginning I felt a little bit nervous to be honest, it was a little bit hot and that’s why I lifted my visor up to get some air and to cool down a bit, but I’m really happy this year.”
Lily Partridge, the first British woman over the line in the elite women’s race, with a time of under two-and-a-half hours, said: “It is unbelievable. I felt absolutely fantastic until 35K (21.8 miles) and then it started to bite. And then it got slowly worse.”
Partridge, who claimed eighth place, added: “It’s only the second time I’ve run past 23 miles and I’ve only ever done the full distance once (during training).”
Hundreds of police officers were on duty to keep around 800,000 spectators and runners safe.
Competitors start from Blackheath, south east London, running a snaking route along both sides of the Thames, finishing on The Mall near Buckingham Palace.
Last year, the event raised £61.5 million for charity, a world record for an annual one-day fundraising event, making the total raised since 1981 around £890 million, organisers said.
A record 386,050 people applied for this year’s race – almost a third more than last year and the highest number for any marathon in the world.