In the English-speaking world, the expression “animal rights movement” is used to designate activist organizations that, since the late 1970s, have denounced the exploitation of animals. By then, however, the history of social movements for the protection of animals was already more than 150 years old. Indeed, since the start of the nineteenth century, activists appalled at the human treatment of animals have mobilized against the brutality of our customary behavior. The initial concern was with the treatment of cattle, and it is only through a gradual sociological process that animal protection extended to pets and then, much later still, to wild species and to their natural environment. This long history of mobilization for the protection of animals is inevitably linked to the evolution, not merely of socially acceptable emotions, but also of the threshold of tolerance of uncontrolled violence. Methodologically, historical analysis has proven essential to reconstruct the genesis of the variety of emotional gratifications thanks to which animal advocacy can still today mobilize activists of widely varying sociological profiles.