In October 1934 thousands of leftists took up arms in a two-week revolutionary insurrection in the northern Spanish region of Asturias which shook the Second Republic (1931–1936) and formed part of a critical European juncture of protest in 1934. This article rethinks the process of radicalisation—a key process for understanding both the insurrection and the wider polarisation of Spanish society prior to the Civil War—in the context of the Asturian coalfields. I argue that radicalisation, understood as a more militant, confrontational mode of politics, rather than as having any particular ideological content, needs to be located in the struggles, divisions and anxieties at a local level, shaped by understandings of community, within the wid...