This is a comprehensive study in English of political thought in Spain during the Renaissance. In the early sixteenth century Castile experienced two major constitutional crises caused by the accession of a Habsburg ruler (shortly to become Holy Roman Emperor) to her throne, and by the discovery and conquest of America. Politically, these circumstances created a bizarre situation in which the venerable idea of medieval empire was forced to co-exist with a novel, imperial vision made inevitable by expansion in the new world. The strain imposed on Castile's constitutional fabric stimulated the...