グレゴリウス改革
In 1067 Archbishop Guido of Milan, facing the rising forces of the "pataria" reformers in the city, gave up his see. He recommended the subdeacon Gotofredo da Castiglione his successor, who, however, was excommunicated by Pope Alexander II. While Henry IV appointed Gotofredo in 1070, the patarines elected Atto archbishop. Three years later Pope Alexander II died and was succeeded by Hildebrand of Soana, who named himself Pope Gregory VII. An ardent proponent of the papal supremacy over Henry's emperorship, he promoted the Gregorian Reform as expressed in the "Dictatus papae" of March 1075, including the principle that the papal title is unique in the world and that it may even be permitted to him to depose emperors.