This dissertation deals with aristocratic historiography and political legitimation in late-medieval Portugal (late thirteenth and fourteenth centuries). It offers a perspective into the historical imaginary of the late-medieval Portuguese aristocracy; an imaginary that underlay the argumentation of members of this social class in defence of their traditional rights and jurisdictions against political centralisation. It examines how the medieval Portuguese aristocracy utilized memories of past interactions with Islam to justify its privileged social status and
defend its traditional prerogatives at a time when this social group opposed the royalist policy of political centralization. This research is included into wider debates on the role of culture — in this case, historical culture — as a resource to justify, reinforce, reproduce, and transform an existing social order.

When confronting royalty over the ongoing process of monarchical centralisation, the Portuguese aristocracy invoked the war against Islam as the primary argument for its social prominence and the source of its class privileges. The sources studied in this thesis were part of the aristocracy’s political legitimation discourse. They provided the nobility with an indispensable social role for the equilibrium of an idealised social order, while reality was ridden with contradictions and in rapid transformation.