The imperious spirit of Frederick, unwilling to brook interference in the affairs of his kingdom even from his feudal superior, first disclosed itself when he was but fourteen years old in a dispute with the clergy of Palermo, who appealed from his decision to the Pope. His defiance of the Pontiff was subsequently of such frequent occurrence as to be regarded as one of the leading principles of his administration. Innocent seems to have viewed with almost paternal indulgence the disobedience of a youth of excellent parts and undaunted resolution, who was subject to his authority not only as a member of the Christian communion, but in the double capacity of ward and vassal. His inability to appreciate the true character of Frederick was never so apparent as when he committed the fatal error which raised that prince to the greatest throne in Christendom. The paltry concessions extorted as the price of this great dignity were an indifferent compensation for the series of misfortunes its bestowal entailed upon Europe,--the rancorous hostility of faction; the perpetuation of intestine conflict, with its inseparable evils, widespread anarchy, the destruction of cities, the waste of provinces, the massacre of non-combatants, the obstruction of national progress; and the partial return to the barbarous conditions of former ages induced by the relentless strife of Guelf and Ghibelline. It is not the object of this work to minutely set forth the events of that mighty struggle. The relations of the Holy See and the Empire are only important as they may have affected indirectly the influence of the reforms instituted by the great Emperor; reforms whose foundation had been laid by two preceding dynasties of widely different character, and whose principles derived their origin from the colonization of Sicily by a nation utterly foreign to the laws and traditions of contemporaneous Europe.