Marathon world record progression races were first held in 1896, but the distance was not standardized by the International Association of Athletics Federations (IAAF) until 1921. The actual distance for pre-1921 races frequently varied slightly from the present figure of 42.195 km (26 miles 385 yards). In qualifying races for the 1896 Summer Olympics, Greek runners Charilaos Vasilakos (3:18:00) and Ioannis Lavrentis (3:11:27) won the first two modern marathons. On April 10, 1896, Spiridon Louis of Greece won the first Olympic marathon in Athens, Greece in a time of 2:58:50; however, the distance for the event was reported to be only 40,000 meters. Three
Athletics at the 1908 Summer Olympics – Men's marathon yards on the track") eventually became the origin of the modern Marathon distance of "no less than 42.195 km". According to the book "The Marathon Makers" by John Bryant, the first mile of the 1908 Olympic Marathon course was remeasured by John Disley in the late 1990s and was found to be 174 yards (159 m) short. The official report lists the leaders at each mile from the fourth to the twenty-fourth: Thomas Jack (miles 4–5); Frederick Lord (miles 6–14); Charles Hefferon (miles 15–24). Dorando Pietri of Italy caught Hefferon and sped up between Old Oak Common Lane and Wormwood