The World Championships in Athletics is an event organized by the International Association of Athletics Federations (IAAF). Originally, it was planned to be held every four years, but this changed after the third edition in 1991, and it has since been run biennially.
The idea of having an Athletics World Championships was around well before the competition's first event in 1983. In 1913, the IAAF decided that the Olympic Games would serve as the World Championships for athletics. This was considered suitable for over 50 years until in the late 1960s the desire of many IAAF members to have their own World Championships began to grow. In 1976 at the IAAF Council Meeting in Puerto Rico an Athletics World Championships separate from the Olympic Games was approved.
Over the years the competition has grown in size. In 1983 an estimated 1,300 athletes from 154 countries participated. By the 2003 competition, in Paris, it had grown to 1,907 athletes from 203 countries with coverage being transmitted to 179 different countries.
There has also been a change in composition over the years, with several new events, all for women, being added. By 2005 the schedule for men and women was almost equal. The only differences being the men had the extra event of the 50 km walk, while women competed in the 100 m hurdles and heptathlon compared to the men in the 110 m hurdles and decathlon respectively.
The following list shows when new events were added for the first time.
The opening and closing ceremonies of the 8th IAAF World Championships held in Edmonton in 2001 were broadcast live to over 200 countries. The event included the men's marathon, and featured a thousand voice choir and original music by The Second City alumni Jan Randall.