Swimming has been held at every Olympic Games. The early events were usually only conducted in freestyle (crawl) or breaststroke. Backstroke was added as of the 1904 Games. In the 1940s, breaststrokers discovered they could go much faster by bringing both arms overhead together. This was banned in the breaststroke shortly thereafter but became the butterfly stroke, which is now the fourth stroke used in competitive swimming. Women's swimming was first held at the 1912 Olympics. It has since been conducted at all the Olympics. Men and women compete in an almost identical programme. They have the same number of events but the freestyle distance for women is 800 metres while for men it is 1500 metres.

(BOCOG)