It's the 37th annual London Marathon.
Always one of the biggest events in the sporting calendar, and this year is no different with close to 40,000 people pounding the streets of the city centre.
The race begins in Greenwich Park, with elite runners and charity fundraisers heading through Woolwich and round past the Cutty Sark.
Runners then go around Rotherhithe, over Tower Bridge towards Canary Wharf, where th athletes then double back and head west along the Thames, along Embankment, past the Houses of Parliament, then Buckingham Palace before the finish line on The Mall.
Security has been ramped up ahead of this year's event in light of the recent Westminster terror attack.
London Marathon 2017
We've got a roving reporter on the ground, ready to catch up with some of the fun runners and the fans, while also chatting to some of the elite runners at the finish line.
For all the action, check out our live blog below.
Key Events
That's that
Well it’s been a great day. What an occasion. Thanks for joining us on our live coverage. See you next year...
Last legs
The end of the day
Here’s reporter Tom Moore summing up an incredible day’s action.
Chappers
Here’s Match of the Day 2 host Mark Chapman.
Call the Midwife
Not for a birth, but one of the stars of the hit BBC show was running the marathon today.
Royal hug
Celeb chat
There were a number of celebrities running today. Here’s one chatting to our own Tom Moore...
And another
So many like this
Not many to go...
35,000 runners have now crossed the line, with around 4,000 still to go.
Well said
Congrats to all
James Cracknell for MP?
James Cracknell was pleased with his run today...
Funny, but not funny...
Love this
The Royals
Stars
Man of the moment
Here’s Josh Griffiths.
Mary Keitany speaks
Here’s the women’s race winner...
Agreed
Josh Griffiths
There’s lots of interest in Josh Griffiths, as you might expect, our man Tom Moore is waiting patiently to have a chat with him.
Fancy dress
There are always lots of people running in fancy dress. Here’s the best of them. Joe Spraggins was the first in fancy dress to cross the line today.
Josh Griffiths
Griffiths: “Thought with the Commonwealth Games I’d give the marathon a shot. I never considered the World Champs until I crossed the line.”
Josh Griffiths is on BBC now: “My first marathon today, I never even considered a British place, it was always to qualify for Commonwealth Games for Wales.”
Swansea Harriers
Help
It’s all about Swansea Harriers today as another Swansea Harrier has stopped to help a Chorlton Runner, clearly struggling by the finish, to get over the line. Unbelievable spirit.
More congratulations
Where's Josh?
We are trying to track down Josh Griffiths. As a club runner he doesn’t have to come through the mixed zone, where our man on the ground is...
Well done
Josh Griffiths
The Swansea Harrier ran the Llanelli half marathon in 1:05:18 last month, but this was his first marathon run. And what a run.
Keitany and Wanjiru
Mary Keitany: “It was a great day for me, I led all the way and I thank God. It was really amazing, a great day for me.”
Daniel Wanjiru: “In the beginning the race was very fast, anything can happen, it was good for me, I was preparing to come and win.”
Debut
That was Josh Griffiths’ debut marathon! Amazing.
Josh Griffiths
He is the Swansea Harrier, he’s clocked 2:14:49 and the club runner is the first Brit across the line. He’s got the qualifying time for the World Championships!
Swansea Harrier
A Swansea Harrier may have crossed the line as the first British athlete...
The good stuff
Right then, now that elite business is over, where are the real runners? Let’s see how the masses are getting on...
Sunshine
What a race!
Daniel Wanjiru found something there to hold off Kenenisa Bekele, who looked out of it halfway through, but found something in reserve to claw back the field and almost take the title.
WANJIRU WINS!
Daniel Wanjiru wins the London Marathon 2017!
Wanjiru
It’s going to be Daniel Wanjiru, he’s holding off the great Kenenisa Bekele
Last 600 metres
Bekele closes the gap, Wanjiru opens bigger gap...who’s going to win it?
Battle
Good pic
Bekele v Wanjiru
Looks like Daniel Wanjiru has only just realised who it is behind him, and has stepped it up. Who will come out on top?
Beast
Bekele
He is chasing down Daniel Wanjiru...Kenenisa Bekele looked out of it earlier, but it looks like he’s going to chase down the leader and win the London Marathon!
Those trying to go about their business...
Anyone else feel like this?
Excitement
This men’s race is set for an exciting finish...Kenenisa Bekele is back in it, chasing down Daniel Wanjiru...
Purdue
And Charlotte Purdue follows her home with a sub 2:30 time too.