When was the game of soccer invented?

http://worldsoccer.about.com/cs/historyandstats/a/sochistart.htm "There is documentary evidence that a a game or skill building exercise, involving kicking a ball into a small net, was used by the Chinese military during the Han Dynasty - around the 2nd and 3rd centuries BC. Earlier evidence - of a field marked out to play a ball-kicking game has been found at Kyoto, in Japan." www.fifa.com also has an article about the history of soccer that credits the Chinese with inventing the game.