The countdown has begun to the world's most famous road running event, the Flora London Marathon, on 13 April.
Length: 26.2 miles
Finishers so far: 508,340
2003 entrants: Approx 33,000
Prize money: $55,000 each
Men: Khalid Khannouchi (USA)
Women: Paula Radcliffe (GBR)
Around 33,000 runners are getting ready for the challenge of a lifetime - a gruelling 26.2-mile journey through the streets of London.
The 23rd London Marathon promises to have all the action, fun and excitement that has made the event so popular with millions of spectators.
The race from Greenwich to The Mall has a universal appeal, and not only includes some of the fastest runners in the world, but also athletes of all abilities.
Britain's club runners, wheelchair racers, marathon novices and fun runners dedicated to charity fundraising, will also be in action.
The Elite Races
Now in its 23rd year, the London Marathon boasts the most competitive international fields of any of the world marathons.
Men: Khalid Khannouchi (USA) - 2.05:38 in 2002
Women: Paula Radcliffe (GBR) - 2.18:56 in 2002
Women (mixed race): Ingrid Kristiansen (NOR) - 2.24:06 in 1985
Despite the withdrawal of Khalid Khannouchi, the event sees the return of fellow world record holder and 2002 champion Paula Radcliffe in the women's race.
The British star is likely to face a tough challenge from double Chicago Marathon winner Catherine Ndereba of Kenya, as well as a familiar foe from her track days, Derartu Tulu of Ethiopia.
In the men's race, Kenyan Paul Tergat is still looking for his first win in London, but might struggle to keep reigning Olympic and world champion Gezahegne Abera at bay.
The Wheelchair Marathon
Some of the world's best wheelchair athletes travel to London to compete.
Denis Lemeunier leads the strong French contingent as he seeks to win back his men's title, while Tanni Grey-Thompson will be aiming to win her seventh race in London.
The Mass Race
Tens of thousands of runners of mixed ability will take to the streets of the UK capital.
They will be testing themselves to the limit, but for many, in fancy dress, the emphasis is on 'fun' and raising money for charity.
The London Marathon, which raised £31m for charity in 2002, has become Britain's number one annual charity fundraising event.
The official charity for this year's race is Shelter, which provides vital work with the homeless and poorly housed families.
The 1000 Miles Challenge
On the morning of 13 April, five plucky Brits will finish a gruelling challenge which began six weeks before.
Reviving an endurance legacy first completed almost 200 years ago by Captain Robert Barclay Allardice, the determined bunch are attempting to run one mile every hour for a period of 1000 hours.
The challenge has already taken its toll after one of the six original competitors was forced to drop out.
The final mile of the incredible event is scheduled for completion in Greenwich at 0800 BST on Marathon Race Day
The Mini London Marathons
Youngsters between 11-17 years of age can also get in the act by taking part in the mini marathon or the mini wheelchair race.
More than 2,000 children are set to take part in the Adidas Mini London Marathon, which is run over the last 2.65 miles of the course.
The Adidas Mini London Wheelchair Marathon, which starts at Victoria Embankment and finishes in The Mall, is open to young wheelchair athletes from the London Boroughs, and invited individuals across the country.
Starting times for the 2003 Flora London Marathon
0900 - Elite women
0915 - Wheelchair and mini marathon
0945 - Elite men and mass start