Why is the length of the marathon 26 miles and 285 yards?

Answer 1

The length of a marathon was not fixed in 1908. When London was awarded the games, the race was advertised as about 25 miles or 40 kilometres. When it was decided to start the race near Windsor Castle, and run past Eton and Harrow (famous public schools), it was obvious that it would be more like 26 miles. Mile markers from the start were cemented in place before the stadium was finished, so although the course of the race was known, its exact distance wasn't. In the end it turned out to be 26 miles 385 yards, or 42.195 metres. The next two Olympics used different distances, but the London one became standard during a meeting of the IAAF in 1921.