why is a marathon 26.2 miles

A marathon is 26.2 miles long because of a historical decision made during the 1908 London Olympics. Originally, marathon races were about 25 miles, inspired by the ancient Greek story of Pheidippides running from Marathon to Athens. However, in 1908, the British royal family requested that the race start at Windsor Castle and finish in front of the royal box at the Olympic stadium. To accommodate this, the course was extended by 385 yards, making the distance 26 miles and 385 yards (26.2 miles). This length was later formalized as the official marathon distance in 1921 and has been standardized globally since then.