JOHN XII., pope from 955 to 964, was the son of Alberic, whom he succeeded as patrician of Rome in 954, being then only sixteen years of age. His original name was Octavian, but when he assumed the papal tiara as successor to Agapetus II., he adopted the apostolic name of John, the first example, it is said, of the custom of altering the surname in connexion with elevation to the papal chair. As a temporal ruler John was devoid of the vigour and firmness of his father, and his union of the papal office—which through his scandalous private life he made a byword of reproach—with his civil dignities proved a source of weakness rather than of strength. In order to protect himself against the intrigues in Rome and the power of Berengar II. of Italy, he called to his aid Otto the Great of Germany, to whom he granted the imperial crown in 962. Even before Otto left Rome the pope had, however, repented of his recognition of a power which threatened altogether to overshadow his authority, and had begun to conspire against the new emperor. His intrigues were discovered by Otto, who, after he had defeated and taken prisoner Berengar, returned to Rome and summoned a council which deposed John, who was in hiding in the mountains of Campania, and elected Leo VIII. in his stead. An attempt at an insurrection was made by the inhabitants of Rome even before Otto left the city, and on his departure John returned at the head of a formidable company of friends and retainers, and caused Leo to seek safety in immediate flight. Otto determined to make an effort in support of Leo, but before he reached the city John had died, in what manner is uncertain, and Benedict V. had mounted the papal chair.