human
Why is a marathon 26.2 miles? Is it a round number in the metric system? How was the length of the race set?
gpt
The origin of the modern marathon, a foot race of **26.2 miles** or **42.195 kilometers**, dates back to the **1896 Olympics** held in **Athens, Greece**. The race was inspired by the legend of the ancient Greek messenger *Pheidippides* who ran from Marathon to Athens, a distance of approximately 40 kilometers or nearly 25 miles, to deliver the news of a crucial Greek victory over the Persians in 490 B.C. Despite collapsing and dying from exhaustion after completing his mission, the messenger's run was commemorated by setting the distance of the 1896 Olympic marathon at 40 kilometers.

In subsequent Olympics, the marathon remained close to 25 miles, but at the 1908 Games in London, the length of the race was extended. This was allegedly done to please *Queen Alexandra*, who requested that the marathon *start on the lawn of Windsor Castle and finish in front of the royal box at the Olympic stadium*. The resulting distance was **26 miles and 385 yards**. The new length ended up sticking, and *in 1921 it was officially standardized as the length of a marathon*. While the roots of the marathon may be ancient, its modern length owes its origin to a combination of legend and royal preference.