A charity fundraiser will today run the final leg of his challenge to complete 401 marathons in 401 days.
Ben Smith, 34, will have covered 10,506.2 miles since September 1 2015, equal to running from London to Sydney.
He is running to raise awareness of bullying of young people, with the money collected shared between charities Stonewall and Kidscape.
Throughout the challenge, he has battled injuries including a long-standing spinal problem and pain in his kneecaps, heels and shins.
His injuries prevented him from running a marathon for 401 consecutive days but he has kept to his schedule by making up the lost mileage.
Local running groups have supported Mr Smith in creating each of his routes and more than 9,000 people have joined him.
Hundreds of runners will join Mr Smith in Bristol, while more than 1,000 will take part in the final leg of his mammoth challenge virtually.
He will set off from Millennium Square in Bristol, running to Portishead and back with 401 supporters.
The marathon will finish at Millennium Square, where Mr Smith will deliver his final motivational speech of the challenge.
"It's been an emotional journey over the past four years," Mr Smith said.
"A lot has changed in my life including coming to terms with who I really am and what I am on this earth to do.
"Having gone from not being able to run for a bus to being on the cusp of running my 401st marathon, I am truly grateful to everyone that has been involved in getting me to this point.
"I have grown in confidence and belief in my ability and have been overwhelmed by the support everyone has shown both me and the project.
"Bullying touches everyone. This project has been an opportunity to bring the issues of bullying to the forefront of people's mind and has for many been a source of inspiration and change.
"I'm proud of what both myself and the team have accomplished and I am looking forward to the future and the positive change we can bring with The 401 Foundation."
Mr Smith completed his 399th marathon at Bournemouth Marathon on Sunday, where he was given the honour of starting the race.
During the challenge, he has participated in marathons including the Isle of Wight, Bristol to Bath, Brighton, Greater Manchester, Milton Keynes, Edinburgh and the London Marathon.
He aims to raise £250,000 for the charities and has given 101 motivational talks to schools, colleges and universities to raise awareness of bullying.
Children as young as five have taken part in Mr Smith's challenge, while a Jack Russell named Eddie accompanied him for a marathon run.
Mr Smith twice tried to take his own life and suffered a mini-stroke aged 29 following years of bullying and physical abuse at boarding school.
A friend encouraged him to join a running club during his recovery and he found it helped him regain mental and physical health.
After coming out as gay, Mr Smith wanted to do something to raise awareness of the damage that bullying can do as well as raise money to support relevant charities.
To follow Mr Smith's challenge go to www.the401challenge.co.uk.