Handball developed in the late 19th and early 20th century in Germany, Denmark and Sweden, although the rules differed per country. An international federation, the International Amateur Handball Federation, was founded during the 1928 Olympics. In 1933, the outdoor variety of the sport was picked to be held at the 1936 Olympics. This version, played on football pitch with 11 players aside has since become less popular and World Championships in the sport have not been held after 1966, yielding to the present form of indoor handball.