The inaugural London Marathon was run on March 29th 1981 proving an instant success. More than 20,000 people applied to run: 7,747 were accepted and 6,255 crossed the finish line on Constitution Hill as cheering crowds lined the route. Now at capacity, a total of 46,500 were accepted from a record 80,500 applicants, with 32,563 finishing on the day. Since this time the event has continued to grow in size, stature and popularity with a capacity 46,500 accepted entrants each year. In all, a total of 676,743 have completed the race since its inception with a record 35,674 crossing the line in 2007.

As a fundraising event, there is no marathon in the world that comes close to the Virgin London Marathon. One of the dominant images of the race is that of thousands clad in fancy dress, tramping the cobbles in support of charitable causes dressed as rhinos, football team mascots, giant trees and the like.

In 2002 a biennial survey by The London Marathon Ltd reported that a record £31 million had been raised, a 25% increase on the 2000 figure. Since 1981 it is estimated that over £200 million has been raised for charities world-wide with 76% of competitors running for a cause close to their hearts. One third of the total amount of places offered to runners comes from charities who are awarded guaranteed places or Golden Bonds.

The London Marathon also has its own Charitable Trust which distributes all profits made from their events to fund and part-fund recreational projects across the capital. Since the first London Marathon in 1981 over £12million has been given in grants by the Trust to local community projects examples include: sports equipment for schools and community groups; ramps and lifts to help disabled people enjoy sports; establishing nature trails and to improve existing leisure facilities.

In 1999 The London Marathon Charitable Trust purchased its first playing fields, as a way of keeping land for sport rather than possible development. The London Marathon Playing Fields in Greenwich are being used as an FA regional mini-soccer centre. The Trustees of the LMCT have established a 'War Chest' of funds to enable the future purchase of playing fields as part of an ongoing London Marathon Playing Fields scheme.