The marathon distance has always been 42.195 km.

False! The marathon distance of 42.195 kilometers was actually standardized only in 1921 by the International Amateur Athletic Federation (IAAF), now known as World Athletics. Before that, the distance often varied between different races and even during the early Olympic Games. The specific length of 42.195 km originates from the 1908 London Olympics, where the race was extended so the finish line would be directly in front of the royal family's box at White City Stadium.