b. c. 937
d. May 14, 964

John XII (938-964) was the son of Alberic 11, the civil ruler of the eternal city, and connected to other patrician families. On being elected pope at the age of eighteen, he modeled himself on the scandalous Roman emperor Heliogabalus, holding homosexual orgies in the papal palace. To counter opposition to his rule, he invited the German ruler Otto the Great to Rome, where he was crowned emperor in 962. John was thus instrumental in establishing the Holy Roman Empire, an institution that lasted in a formal sense until 1806

John’s activities may have helped to incite the reaction of the puritanical theologian Peter Damian (1 007-1072), whose Liber Gomorrhianus is an attack against all kinds of sexual irregularities among the clergy. Under his associate Pope Gregory VII (ca. 1021-1085) reform ideas triumphed, and clerical celibacy was made obligatory for the Catholic priesthood, an injunction that remains in force to this day.