The true origins of the marathon are tangled in the legend of Pheidippides. The messenger is supposed to have run without pause from the plain of Marathon to Athens with news of victory in a crucial battle against the invading Persian Army. After announcing the triumph to the city, he then dropped dead, apparently of exhaustion.
After Robert Browning seized on the myth of Pheidippides in a poem that inspired Baron Pierre de Coubertin, the father of the modern Olympics (there was no marathon at the ancient games), the event debuted at the inaugural Olympiad in Athens. Victory went to Greek water carrier turned national hero, Spyridon Louis.
Long-distance running had already been popular among wealthy gamblers but the Athens marathon captured the public imagination. Arthur Blake, an American competitor in 1896, returned to his home in Boston to launch the first annual marathon. But it would not become a mass-participation event for several decades.
Race distances varied but stood at about 25 miles (40km). When the marathon came to the London Olympics, the course, from Windsor Castle to the new White City Stadium in West London, was extended to finish in front of the royal box. The distance of 42,195m (26 miles and 385 yards) would become the standard.
Huge interest in the Windsor event inspired its organisers, the Polytechnic Harriers, to establish an annual race over a similar course. The Polytechnic Marathon, which ran until 1996, was the stage for a string of record-breaking feats. In 1953, Jim Peters broke the 2hr20m barrier (then the equivalent of the four-minute mile).
Tapping into the Seventies jogging boom, the New York Road Runners Club took the city's marathon out of the confines of Central Park to take in the entire city. The first marathon for the masses, watched by the masses, it launched the era of the big city race. It remains the world's biggest; 43,000 competitors finished in 2009.
Awed by the New York race, which he called "the greatest folk festival the world has seen," Chris Brasher joined forces with fellow Olympian, John Disley, to launch the London Marathon. Now the stage for the blood, sweat and tears of more than 30,000 runners every year, it has become one of the world's greatest marathons.
Paula Radcliffe's stunning marathon debut in 2002 launched her as one of the greatest female distance runners of all time. In London the following year, she broke her own world record, which still stands, with a time of 2:15:25. Haile Gebrselassie set the current men's world record in Berlin in 2008 with a time of 2:03:59.