Sydney Football Stadium, 28 September 2000, Games of the XXVII Olympiad: Mia Hamm of the USA (N°9) battling with Hege RIISE (N°6) of Norway during the football final. Norway went on to win the gold medal. Credit: Getty Images/Shaun Botterill

While the modern game of football started with the foundation of the Football Association of England in 1863, its roots extend to opposite ends of the earth. The ancient Chinese, Greeks and Romans played a similar game, long before English kings in the 1300s and 1400s were trying to outlaw the violent sport.

While professionals are allowed in the men’s tournament, rules restrict teams to players under 23 years old with the exception of three over-age players. ’No age restrictions apply for the women’s tournament. For the Beijing 2008 Games the number of women’s teams has been increased to 12. The men’s tournament is set at 16 teams.