What determines violent reaction during state formation processes? To address this question, we exploit the uprisings that occurred when southern Italy was annexed to Piedmont during Italian unification in the 1860s. We assemble a novel dataset on episodes of brigandage, a form of violent rebellion against the unitary government, and on pre-unification social and economic characteristics of southern Italian municipalities. We find that the intensity of brigandage is ceteris paribus lower in and close to settlements of Piedmontese origin. We argue that geographical distance from these communities is a proxy for cultural distance from the Piedmontese rulers. Thus, our results suggest that, in the context of state formation, cultural proximity to the new ruler reduces social unrest by local communities. After ruling out alternative mechanisms consistent with the economic literature, we provide suggestive evidence of cultural persistence and diffusion in our context, and discuss two possible culture-based drivers of our results: social identification with the Piedmontese rulers, and a clash between local values and some specific content of the new institutions.