The struggle between Frederick II and the papacy is the most dramatic of all the medieval contests between Regnum and Sacerdotium and has naturally attracted many historians. Frederick's relations to the church of his Sicilian kingdom is a less obviously dramatic theme and has never been treated except incidentally as one of the contributory causes of friction between pope and emperor. It is, however, worthy of independent study, providing as it does a corrective to the idea of Frederick engaged in almost ceaseless warfare against the church, which one derives from excessive concentration on papal and imperial manifestoes. A study of Frederick's Sicilian constitutions, of his charters to churches and his letters to officials and ecclesiastics, reveals a ruler who is far from being the inveterate enemy of churchmen and of church privileges.