15. Sixtus IV had several illegitimate children while taxing priests who had mistresses
During his thirteen year reign (1471-1484) Sixtus IV developed a reputation for nepotism and involvement in conspiracies. One was the Pazzi Conspiracy, an attempt by members of the Pazzi family to murder Giuliano and Lorenzo de Medici. Pope Sixtus was a leading instigator of the conspiracy, which led to the death of Giuliano and Lorenzo being severely wounded, though he survived. The failure of the Pazzi conspiracy led to the Pazzi family’s banishment from Florence, and to Lorenzo’s increased enmity towards the pope. Sixtus responded by placing Florence under interdiction, forbidding the saying of Mass and the sacraments from being given.
Despite being a party to an attempted double murder, Sixtus’s papacy continued until his death in 1484, having only succeeding in strengthening the power and influence of the Medicis in the Italy, and gaining them the sympathy of the Neapolitans. Sixtus strengthened his papacy by ensuring his relatives and friends held positions of authority which were also capable of creating wealth by extracting it from other Catholics. Priests were banned from having mistresses unless they paid a tax to his office. The tax did not extend to the many mistresses he maintained during his reign. Primarily though, his interests were of a temporal nature, and he fortified the Papal States against attacks from his enemies.