[X] Add Avignon papacy and Great Western Papal Schism. There have been a LOT of bad popes!
Pope John XII 955-963 Described by the Catholic Encyclopedia as "a coarse, immoral man, whose life was such that the Lateran palace was spoken of as a brothel, and the moral corruption in Rome became the subject of general disgrace." Pope Benedict IX 1032-1045 A murderer and an adulterer; the Catholic Encyclopedia admits he lived a "dissolute life" and was "a disgrace to the Chair of Peter." "One of the youngest popes, he was the only man to have been Pope on more than one occasion [three times!] and the only man ever to have sold the papacy." Pope Sixtus IV 1471-1484 Allegedly erected a house of prostitution in Rome. (There are questions about this fact, specifically that the only real source for it comes from an early Protestant writer and hardcore anti-catholic... hardly unbiased evidence.) Established the Sistine Chapel. Unquestionably guilty of nepotism. Pope Pius II 1458-1464 Had two illegitimate children before he entered the clergy. Wrote some erotic works. Pope Innocent VIII 1484-1492 Had at least two illegitimate children before he became Pope. As Pope, he raised his children to positions of authority and wealth in the Catholic Church. Guilty of simony. Pope Alexander VI 1492-1503 Had at least four illegitimate children whom he then made rich through ecclesial appointments. He made his son, Caesar Borgia, a cardinal when he was only 18 years old. Caesar was an immoral and violent man who had his brother put to death as well as his sister Lucrezia’s husband. Pope Alexander held unspeakable orgies in his palace and kept mistresses who were married women. He died of syphilis. Pope Julius II 1503-1513 Had at least three illegitimate children before becoming pope.