For the moment Innocent’s iron policy crushed opposition, but in adding the new hostility of the national kings and the rising nations of Europe to the old hostility of the declining empire, Innocent was entering into a perilous course of conduct, which, within a century, was to prove fatal to one of the strongest of his successors.  The more political the papal authority became, the more difficult it was to uphold its prestige as the source of law, of morality, of religion.  Innocent himself did not lose sight of the higher ideal because he strove so firmly after more earthly aims.  His successors were not always so able or so high-minded.  And it was as the protectors of the people, not as the enemies of their political rights, that the great popes of the eleventh and twelfth centuries had obtained their wonderful ascendency over the best minds of Europe.

The coronation of Otto IV did not end Innocent’s troubles with the Empire.  It was soon followed by an open breach between the Pope and his nominee, from which ultimately developed something like a general European war, between a league of partisans of the Pope and a league of partisans of Otto.  It was inevitable that Otto, as a crowned emperor, should look upon the papal power in a way very different from that in which he had regarded it when a faction leader struggling for the crown.  Then the support of the Pope was indispensable.  Now the autocracy of the Pope was to be feared.  The Hohenstaufen ministeriales, who now surrounded the Guelfic Emperor, raised his ideals and modified his policy.  Henry of Kalden, the old minister of Henry VI, was now his closest confidant, and under his direction it soon became Otto’s ambition to continue the policy of the Hohenstaufen.  The great object of Henry VI had been the union of Sicily with the Empire.  To the alarm and disgust of Innocent, his ancient dependent now strove to continue Henry VI’s policy by driving out Henry VI’s son from his Sicilian inheritance.  Otto now established relations with Diepold and the other German adventurers, who still defied Frederick II and the Pope in Apulia.  He soon claimed the inheritance of Matilda as well as the Sicilian monarchy.  In August, 1210, he occupied Matilda’s Tuscan lands, and in November invaded Apulia, and prepared to despatch a Pisan fleet against Sicily.  Innocent was moved to a terrible wrath.  On hearing of the capture of Capua, and the revolt of Salerno and Naples, he excommunicated the Emperor and freed his subjects from their oaths of fealty to him.  But, despite the threats of the Church, Otto conquered most of Apulia and was equally successful in reviving the Imperial authority in Northern Italy.