The Olympic Marathon Distance Was Set by Accident

The modern marathon's exacting length of 42.195 kilometers, or 26.2 miles, owes its existence to a blend of historical homage and royal accommodation. The race's origins are rooted in the legend of Pheidippides, a Greek messenger who is said to have run approximately 40 kilometers from Marathon to Athens to announce a military victory in 490 B.C. When the modern Olympic Games were inaugurated in 1896, the marathon was introduced as a featured event, with a distance that approximated the legendary run. For the first several modern Olympics, the marathon's length varied, depending on the specific course laid out by each host city.

The pivotal moment in standardizing the distance came at the 1908 London Olympics. Organizers planned a course of about 25 miles, but a last-minute adjustment was made to accommodate the British royal family. The starting line was moved to the East Lawn of Windsor Castle, reportedly so the royal children could watch from their nursery window. The finish line was then extended to be directly in front of the royal box at the White City Stadium. This royal-centric route resulted in a total distance of 26 miles and 385 yards.

This rather arbitrary distance might have remained a historical footnote, but the dramatic finish of the 1908 race, where Italian runner Dorando Pietri collapsed and was controversially helped over the line, captured the public's imagination. The fame of this event helped to cement the new distance in the minds of the athletic community. For over a decade, marathon distances continued to fluctuate. Finally, in 1921, the International Amateur Athletic Federation officially sanctioned the 42.195-kilometer distance from the 1908 London Games as the official length for all future marathons, a standard that remains to this day.