This proposition startled Henry; he saw the ambitious designs of the pope, and he felt the importance of checking them. Boldly denying the papal pretensions, and rejecting with indignant contempt the proposition of Paschal, he marched his army on Rome, dragged the pope from the altar while he was celebrating mass, and casting him into prison, determined that he should there remain until he consented to crown him without any condition. To be restored to liberty and luxury the pope acceded to all the terms dictated to him by the emperor, but with a secret disposition to render them nugatory at the first opportunity. Disturbances occurring in Germany, the pope was agreeably relieved of the embarrassing restraints of the emperor's presence. To suppress the Germanic revolution the skill and valor of Henry was occupied for two years. In the meantime the pope, in order to nullify the concessions which he had made, organized an Italian conspiracy against the emperor. Soon as Henry had quelled the insubordination in Germany, he therefore returned to Italy to punish the author of the calamities of his reign. But Pope Paschal evaded the designed chastisement by absconding to Apulea, where he shortly afterwards died. Pope Galatius II., an enemy of Henry, having obtained the papal dignity, the latter deposed him, and caused Bourden, under the name of Gregory VIII., to be substituted in his place. The deposed pope and his cardinals, having the control of the papal machinery, were enabled to oppose, with great success, the policy of Henry in every part of his dominion. Galatius assembled a council of bishops at Vienna and excommunicated him; Calaxtus II. convened one at Rheims, and repeated the sentence; the nobles broke out in frequent rebellion; and finally such insubordination prevailed in the empire, and such violent outbursts so frequently disturbed the public peace, that in order to restore tranquillity Henry was compelled to subscribe to a concordat at Worms, in which he renounced the right of investiture, and to any interference in the consecration of bishops.