War was now openly proclaimed; the effect of these letters, thrown broadcast into a kingdom already divided and among a people already discontented and accustomed to rebellion, was immense. Both Church and State were rent in pieces, some taking part with the king, others with the pontiff. A civil war broke out, which raged for seventeen years, throughout the Roman empire; bishop against bishop, the people against the people; "while," says one, "the earth drank up the blood that was shed, and the grave closed alike over those who suffered and those who inflicted the misery." All Germany was in a state of distraction, dissension, and all but prostration.
The dukes of Swabia, taking advantage of the general feeling against Henry, and encouraged by the pope's legates, rose in arms against the sovereign to whom they had sworn fealty, and elected Adolphus as king. In the meantime, Hildebrand himself neglected none of his own means of warfare, a warfare in which he was deeply skilled. Great swelling words of most awful import were his weapons. The "name of God; the peace of God; the commands of God; the salvation of God; the keys of the blessed Peter; closing the gates of heaven; opening the gates of hell; eternal perdition," etc., were words which struck terror into every human mind, and the manacles with which he bound his slaves.
As this great struggle went on, the pope was gathering strength, Henry was losing it and felt it ebbing fast. His heart sank within him: everything seemed blasted by the curse of St. Peter; the princes revolted; the prelates and the people renouncing their allegiance, and conspiracies arose on every side. Such was the evil influence of the pope, who now stepped forth in the full panoply of ecclesiastical, or rather of diabolical, power, to trample in the dust his own liege lord. Under all these depressing and crushing circumstances Henry came to an arrangement with the rebellious princes -that the claims and wrongs of both parties should be submitted to the pope, who was invited to preside at a council to be held at Augsburg for that purpose.