The marathon is 26.2 miles because of the 1908 London Olympics

Most runners know the marathon as 26.2 miles, a distance that feels so fixed it seems ancient. The story is older than modern running, but the exact number is surprisingly modern. It became standard in distance running because of the 1908 London Olympics.

The marathon was inspired by the legend of Pheidippides, the Greek messenger said to have run from Marathon to Athens to announce victory over Persia. When the modern Olympic Games began in 1896, organizers created a long-distance race to honor that tale. Early Olympic marathons were not all the same length. They were roughly 40 kilometers, or about 25 miles, depending on the route chosen by the host city.

In 1908, London organizers planned a course from Windsor Castle to the Olympic Stadium at White City. The start was placed on the castle grounds, reportedly so the royal family’s children could watch. The finish was set in front of the royal box inside the stadium. That particular route measured 26 miles and 385 yards.

The race itself helped make the distance famous. Italian runner Dorando Pietri entered the stadium first but collapsed repeatedly and was assisted across the finish line. He was disqualified, and American Johnny Hayes was declared the winner. The dramatic ending drew huge public attention, and the course distance became part of the story.

For a while, marathon distances still varied. But in 1921, the International Amateur Athletic Federation officially adopted the 1908 London distance as the standard: 26 miles, 385 yards, or 26.2 miles. Since then, every official marathon has followed it.

So the marathon is not 26.2 miles because ancient Greeks measured it that way. It is 26.2 miles because a London Olympic course happened to connect a royal starting point with a royal finish line, and history decided to keep it.