Nicholas I. governed by Them.—His Character. Adrian II.—John VIII.—John XII.—Benedict IX.—Three Popes at Same Time.—German Emperors create Popes.—Leo IX.—Hildebrand.—He becomes Pope as Gregory VII.—Principles established by Him. His Quarrel with Philip of France.—His Bull against Henry IV.—He adopts the False Decretals.—Pius IX. does the Same.—Gregory VII. stirs up Revolt in Germany.—The Emperor Henry IV.