Here's some background information about the Summer Olympics, which is held every four years.
Summer Olympics: The first revival of the Olympics was held in Athens, Greece from April 6, 1896 - April 15, 1896.
The first modern Olympic champion was James Connolly (USA), who won the triple jump event.
Fourteen nations and 241 athletes (all men) competed in 43 events at the first modern Olympic Games.
The Olympic Flame was first lit during the opening ceremony of the 1928 Olympic Games in Amsterdam.
1896 - Swimming is part of the first modern Olympic games in Athens. The first events are freestyle and breaststroke.
1900 - Men's water polo is added to the Olympic games in Paris. Backstroke is added to the swimming events.
1904 - Diving is added to the Olympics in St. Louis.
1912 - Women's swimming and diving are added to the Olympics in Stockholm.
1984 - Individual and duet synchronized swimming are added to the Olympics in Los Angeles.
1996 - Synchronized swimming is changed to team competition. Each team has eight members.
2000 - Synchronized diving and women's water polo are added to the Olympics in Sydney. Synchronized swimming is altered again to include both team and duet competition.
2008 - A 10km swimming race, swum in open water rather than a pool, debuts at the Olympics. Both men and women compete.
1900 - Archery is added to the Olympic games in Paris.
1912 - Archery is excluded from the Olympics in Stockholm.
1920 - The last time archery appears in the Olympics until 1972.
1972 - Archery is added back into the Olympic competition in Munich.
1988 - Team archery is added to the Olympics in Seoul.
1992 - The Olympic Round archery format is established at the Olympics in Barcelona.
Athletics (Track & Field)
776 B.C. - Athletics are part of the first ancient Olympic games in Greece.
1896 - Athletics are part of the first modern Olympics in Athens. Competitions included are 100m, 1,500m, 110m hurdles, Marathon, long jump, triple jump, pole vault, discus, shot put and high jump.
1924 - Women's athletics events are added to the Olympics in Amsterdam. Competitions included are 100m, 800m, 4 x 100m, high jump and discus.
1984 - Women's marathon is added to the Olympic games in Los Angeles.
2008 - The women's 3000 meter steeplechase debuts as an Olympic event.
1992 - Badminton is added to the Olympics in Barcelona.
1992 - Baseball is added to the Olympics in Barcelona.
2012 - Baseball is dropped from the Olympics in London.
1904 - Basketball is an exhibition event at the Olympics in St. Louis.
1936 - Men's basketball is added to the Olympics in Berlin.
1976 - Women's basketball is added to the Olympics in Montreal.
1992 - Participation rules are changed to allow professional basketball players to participate on the Olympic teams.
688 B.C. - Boxing is added to the ancient Olympic games.
1896 - A committee decides that boxing is too dangerous for the modern Olympic games.