Book excerpt: This book combines pieces of work on Europe and Latin America, the two continents where football arouses the most ardent passions among its spectators. Curiously, an undertaking to compare on a large scale the forms extreme fandom takes in these two geographical areas is still lacking. A situational analysis of the scientific literature devoted to the subject over the last two or three decades represents a step in this direction, making a scattered store of knowledge accessible. It thus answers a need to clarify regional differences in identities and in the practices of supporters.