The Late Republican to Early Imperial period was one of spectacular territorial expansion into the surrounding ‘tribal periphery’ of the Roman West. There, the indigenous societies were confronted with state-organised warfare on an unprecedented scale and with a range of new military technologies and strategies. The direct societal impact of conquest on the subjected groups varied greatly. Conquest could strengthen certain polities and stimulate processes of state formation, but it could have disastrous effects on other groups. Here I will investigate Roman warfare in the tribal zone, with a special focus on two topics: the use of extreme mass violence against resistant groups, and the relationship between disproportional use of violence and negative ethnic stereotyping of the ‘tribal other’. I hope to show that archaeology can contribute to a wider debate on these topics among historians and anthropologists1 by assessing the short-term demographic impact of conquest.