The marathon takes its name from the ancient Greek battle of Marathon, fought in 490 BCE. According to legend, a Greek messenger named Pheidippides ran from the battlefield at Marathon all the way to Athens to deliver news of the Greek victory over the Persians. The distance he ran is said to have been around 25 miles, and after delivering the message, he collapsed and died. When the modern Olympic Games were revived in 1896, the organizers wanted to honor this famous story by including a long-distance run. The first modern marathon was held that year in Athens, with a course of roughly 24.85 miles between Marathon and the Olympic stadium.

For the first few Olympic marathons, the exact distance varied depending on the city hosting the Games. The 1896 race was about 24.85 miles, the 1900 Paris marathon was around 25 miles, and the 1904 St Louis race was approximately 24.85 miles again. Each marathon was simply set based on what fit the local geography. There was no official rule about the distance, and runners trained for whatever the host city chose. This worked well enough until the 1908 London Olympics, when something happened that would permanently set the distance for the next century.

When London hosted the 1908 Olympics, organizers planned the marathon to start at Windsor Castle, where the British royal family lived, and finish at the Olympic stadium in White City. The original plan called for a course of about 26 miles. However, the royal family wanted the race to start in a specific spot in the castle gardens so the royal children could watch, and they wanted the finish line directly in front of the royal box in the stadium. To accommodate these requests, the course was extended by about 385 yards, bringing the total distance to exactly 26 miles and 385 yards, or 26.2188 miles in decimal form.

For several years after 1908, marathon distances continued to vary from one race to another. But in 1921, the International Association of Athletics Federations officially adopted the 1908 London distance as the standard marathon length. The decision was largely practical — having a single fixed distance allowed runners to compare times across races and tracked records meaningfully. Since then, every Olympic marathon, the World Marathon Majors races in Boston, New York, Chicago, Berlin, London, and Tokyo, and almost every other certified marathon in the world has used the same distance of 26 miles and 385 yards.

The story behind the marathon distance is a perfect example of how sports traditions are shaped by small, sometimes accidental decisions. A specific request from the British royal family in 1908 became the global standard for one of the most popular endurance events in the world. Every marathon runner today, from elite athletes chasing world records to weekend amateurs training for their first race, runs that exact distance because of choices made more than a century ago. Knowing this story turns 26.2 miles from a strange number into a piece of living history, connecting modern runners to the legends of ancient Greece and the practical decisions of the early Olympics.