Pope, a son, of Albeic, and grandson of the profligate and ambitious Marozia, whose vices he seems to have inherited, succeeded to the dignity of Roman patrician upon the death of his father Alberic, and in November, 955, after the death of Agapetus, was elevated to the papal see, though only about sixteen years old. His own name was Octavianus, but as pope he took that of John XII, thus inaugurating the practice which has ever since been followed by the popes of assuming a pontifical name. Ambitious to extend the boundaries of the States of the Church, he soon involved himself in a disastrous war with Berenger II, himself full of ambition, and anxious to become master of Rome. In this most extreme hour of need the pope hesitated not to beseech help from one whom he had formerly declined to receive as worthy of the imperial crown, the emperor Otho I. Daring and indomitable as was the spirit of Otho I, he was no sooner asked by Rome than we find him crossing the Alps with a large army, and, having entered Rome, he secured to the pope not only personal safety, but also confirmed his title to the States of the Church. The extent of these promises, however, has been subject to controversy, and it is not without a reason that the Vatican record, by which Pepin's donation was confirmed and enlarged, is withheld from critical scrutiny. SEE PAPACY. At Pavia, already, Otho had been crowned king of Italy here, at the Eternal City, he received from the pope himself the imperial diadem. "Never did a more important event in history take place, making less impression on those who witnessed it, and less commemorated by subsequent historians, than the coronation of Otho I at Rome in the year 962. By the coronation of Charles 162 years earlier the first foundations had been laid for the empire; by the, coronation of Otho that empire itself was founded afresh, and from that time forwards it had an uninterrupted existence" (Reichel. Rosmai See in the Middle Ages, p. 124). For a short period the spiritual and temporal heads of Christendom seemed to be happily united, but the fickle John, influenced either by mistrust or jealousy, soon again interrupted that happy concord by concocting anew intrigues with Alberia, the son of Berenger. Rumors of the treacherous conduct of John reached the ears of Otho I, but the noble German would hardly believe the reports until some trustworthy officers whom he had hastily dispatched to Italy pronounced them true. The profligacy and vices of the pope were also reported to Otho I, and the latter determined to return to Rome and depose the vicar, if found guilty of the charges preferred against him. A council composed of the first ecclesiastics of Germany, France, and Italy was quickly called by Otho I, he himself presiding, and the vicar of Christ, accused of the crimes of murder, adultery, and perjury, was summoned to appear in defense. Failing to comply with the emperor's request, judgment was pronounced, and he was deposed and excommunicated Dec. 4, 963, and Leo VIII (q.v.) declared his successor. Hardly had the emperor left Rome when John, supported by the Roman nobility, returned, convened another synod at St. Peter's, and caused it to rescind the resolutions of the former one. Otho I, informed of these outrages, was preparing for a return to Rome for the third time, when John suddenly died of apoplexy while he was engaged in an adulterous intrigue, May 14, 964. "He was a man of most licentious habits, associating with women of every station, and filling the Lateran with the noisy profanity of a brothel." Panvinius, in a note to Platina's account of pope Joan, suggests that the licentiousness of John XII, who, among his numerous mistresses, had one called Joan, who exercised the chief influence at Rome during his pontificate, may have given rise to the story of "pope Joan." Comp. Luitprand, Historia Ottonis, in Monum. Germ.
Script. vol. 3; Milman, Lat. Christ. 3, 175 sq.; Neander, Ch. History; Gieseler, Ch. Hist. 2, 350; Reichel, See of Rone in the Middle Ages, p. 121 sq.; Riddle, Papacy, 2, 39 sq. (J.H.W.)