The study examines the relationship between the inquisitor Paul IV and the heterodox Camillo Orsini through the analysis of unpublished sources. The condottiero’s rhetoric, transversal to the factions of the «intransigenti» and «spirituali», was characterized by strong pro-papal and roman-centric tendencies, expressed also in the formula of the «divine calling» to the pope’s service. Carafa publicly presented these elements as proof of the condottiero’s orthodoxy, functionally placing them in opposition to the heresy he accused the Colonna and Habsburgs of.