Three well-defined nuclei of analysis - the revolts of the barons against the king, the people's movements against the magnates and the peasant uprisings against serfdom - are instead the object of the recognition of the imagination that mobilized these social groups carried out by the author by relying on the sources chronicles. The specific demands of libertas - whether those of the barons of the kingdom of Sicily, the popular Florentine Guelphs or the English rebels - always refer to a more universal and abstract conception of freedom, to be understood as a collective and not particular right. A freedom in the singular, therefore, brandished in conflicts that expressed requests for political participation in opposition to powers perceived as tyrannical or arbitrary, or to governments that excluded social groups from the political life of the community.