The IAAF World Championships, commonly referred to as the World Championships in Athletics, is a biennial athletics event organized by the International Association of Athletics Federations (IAAF). The World Championships was started in 1976 in response to the International Olympic Committee dropping the men's 50 km walk from the Olympic athletics programme for the 1976 Montreal Olympics, despite its constant presence at the games since 1932. The IAAF chose to host its own world championship event instead, a month and a half after the Olympics. It was the first World Championships that the IAAF had hosted separate from the Olympic Games. A second limited event was held in 1980, and a major expansion in 1983 is considered the official start of the event. It was then held every four years until 1991, when it switched to a two year cycle.