Where were the first written rules of football drawn up?

Cambridge, in 1848, when students from several public schools met to reconcile the mutually incompatible games they had each grown up with. The Cambridge Rules banned carrying the ball and running with it, which is the fork in the road: the schools that wanted to keep handling went off and eventually codified rugby instead.

The Football Association was founded in a London pub in 1863 and its rules leaned heavily on the Cambridge ones. The argument that split the meeting was hacking - kicking an opponent in the shins - which the pro-handling faction defended as manly and which the FA outlawed. Blackheath walked out over it and became a founding rugby club.

The rule that has shaped the game more than any other is offside, and it was originally far stricter, requiring three defenders between attacker and goal. Reducing that to two in 1925 immediately increased goals per game by about half, and every tactical system since has been a response. Football's history is largely the history of arguments about that one line.