The fifth century BCE exhibited what has generally been termed ‘gang violence’: that is, the deployment of (relatively) well-organised gangs of lower-class men by elite figures, such as Publius Clodius Pulcher and Titus Annius Milo, in their pursuit of specific political purposes. This chapter analyses this phenomenon from the larger perspectives of self-help in Rome, the political violence that had begun to affect Roman civic life in the second century BCE (intensified by the civil war of the eighties BCE), and by way of the institutional and social features of Roman life (e.g. clientele and collegia) that facilitated the creation and exploitation of gangs. It concludes with innovations introduced by Augustus which effectively brought an end to gang violence in the city of Rome.