What happened 1220 AD

Despite his imperial claims, Frederick's rule was a major turning point towards the disintegration of central rule in the Empire. While concentrated on establishing a modern, centralized state in Sicily, he was mostly absent from Germany and issued far-reaching privileges to Germany's secular and ecclesiastical princes: in the 1220 Confoederatio cum principibus ecclesiasticis, Frederick gave up a number of regalia in favor of the bishops, among them tariffs, coining, and fortification.

Pope Innocent III, who feared the threat posed by a union of the empire and Sicily, was now supported by Frederick II, who marched to Germany and defeated Otto. After his victory, Frederick did not act upon his promise to keep the two realms separate. Though he had made his son Henry king of Sicily before marching on Germany, he still reserved real political power for himself. This continued after Frederick was crowned Emperor in 1220. Fearing Frederick's concentration of power, the Pope finally excommunicated the Emperor. Another point of contention was the crusade, which Frederick had promised but repeatedly postponed.