The disintegration of the empire was followed by a hideous degradation of the papacy. But the Saxon line of emperors, the Ottos, sprung from Henry the Fowler, once more revived the empire; the third of them established a worthy pope in Silvester II. But both emperor and pope died just after the eleventh century opened. Elections of popes and anti-popes continued to be accompanied by the gravest scandals, until the Emperor Henry III. (Franconian dynasty) set a succession of Germans on the papal throne. The high character of the pontificate was revived in the persons of Leo IX. and Victor II. (Gebhard of Eichstadt); many abuses were put down or at least checked with a firm hand. But Henry's death weakened the empire, and Stephen IX. added to the rigid enforcement of orthodoxy more peremptory claims for the supremacy of the Holy See. His successor, Nicholas II., strengthened the position as against the empire by securing the support of the fleshly arm--the Normans. His election was an assertion of the right of the cardinals to make their own choice. Alexander II. was chosen in disregard of the Germans and the empire, and the Germans chose an anti-pope. At the back of the Italian papal party was the great Hildebrand. In 1073 Hildebrand himself ascended the papal throne as Gregory VII. With Hildebrand, the great struggle for supremacy between the empire and the papacy was decisively opened. Gregory's aim was to establish a theocracy through an organised dominant priesthood separated from the world, but no less powerful than the secular forces; with the pope, God's mouthpiece, and vice-regent, at its head. The temporal powers were to be instruments in his hand, subject to his supreme authority. Clerical celibacy acquired a political value; the clergy would concentrate on the glory of the Church those ambitions which made laymen seek to aggrandise their families. The collision between Rome and the emperor came quickly. The victory at the outset fell to the pope, and Henry IV. was compelled to humble himself and entreat pardon as a penitent at Canossa. Superficially, the tables were turned later; when Gregory died, Henry was ostensibly victor. But Gregory's successor, Urban, as resolute and more subtle, retrieved what had only been a check. The Crusades, essentially of ecclesiastical inspiration, were given their great impulse by him; they were a movement of Christendom against the Paynim, of the Church against Islam; they centred in the pope, not the emperor, and they made the pope, not the emperor, conspicuously the head of Christendom.