The current, official distance of 26 miles 385 yards was adopted after the 1908 Olympics in London.

In 1966, Roberta Gibb became the first woman to run in a major marathon - the Boston - by hiding behind a bush until the start, then joining the male athletes.

In 1975, Boston became the first marathon to recognize the disabled athletes who are now such an integral feature of the event.

Throughout the century of its existence, region after region has dominated the marathon.

Scandinavia emerged during the Antwerp games of 1920, with 'Flying Fin' Paavo Nurmi becoming a national hero when he broke a seven year-old record by four minutes.

Then it was the turn of the Far East. In 1936, the Korean Sohn Kee Chung won the Olympic marathon in Berlin (although he was forced to run under a Japanese name). His victory signalled the beginning of Korea's mastery of the men's race that was to last for decades.

Japan, on the other hand, has produced a long line of brilliant female marathoners - not least, the winner of the Athens Olympics, Mizuki Noguchi.

Then it was the turn of Africa. Ethiopian Abebe Bikila, one of Haile Salassie's Imperial bodyguards, won the Rome Olympic marathon in 2:15:16. Bare foot!

For twenty years, Ethiopia seemed invincible. But then the Kenyans appeared, almost from nowhere, and stole the marathon crown. Paul Tergat clocked up an astonishing 2:04:55 in Berlin in 2003 - while the new wave of Kenyans includes the awesome Daniel Njenga and Catherine Ndereba.

As the times tumble inexorably down, we can only wonder where the crown will reside next. South Asia and the Arab world have only just begun to flex their muscles.