This essay examines the origins, diffusion and spread of organized groups of young football fans (so‐called ultras) in Spain. The first Spanish ultra groups emerged after the 1982 World Cup held in Spain. Mainly mimicry of both Italian and English supporter styles, the Spanish ultras separated themselves from the indigenous ‘peña’ culture emphasizing instead a more active and visible approach to football fandom. This movement, often heavily supported by the clubs, subsequently spread to other clubs in Spain’s First and Second Divisions. In the second half of the 1980s, mainly due to the increasing politicization of the ultra groups and the eruption of the skinhead youth subculture, violence became an intrinsic feature of the ultra movement and at times created widespread social panic. The escalation of violence finally resulted in the fragmentation and decline of traditional ultra groups and the emergence of alternative fan groups explicitly opposed to violence. These developments set in motion a complex pattern of rivalries and allegiances strongly influencing contemporary Spanish football culture.