It is a culture that has spawned books, films and documentaries, but what exactly is it? Goal takes a look at the phenomenon
Football is a sport that has a global appeal and it plays a prominent role in many societies across the world.
Supporters of the game come from all walks of life and they find common ground in following their favourite teams, displaying their allegiance one way or another.
While many are content to wear their club colours, sing club anthems or simply watch games, certain cultures among supporters veer gleefully towards violence and it is something that has been thoroughly explored in recent years.