Pope Sergius III
Pope Sergius III was elected to the papacy in 898 but rival candidate Pope John IX was also elected and excommunicated Sergius and his followers. From 903 to 904, Antipope Christopher seized the chair by force and magister militum Theopahylact led a revolt against Christopher. He asked that Sergius come to Rome and become the Pope. Sergius agreed and was consecrated Pope Sergius III on January 29, 904.
Pope Sergius III goes down in history for a different type of scandal than many others on this list. He is reputed to be the only Pope to order the murder of another Pope. Soon after taking power he ordered that both Antipope Christopher and Pope Leo V be strangled in their prison cells. It is debated whether both men were murdered, some sources claim that Antipope Christopher was allowed to retire at a monastery.
There is some debate about whether or not the murders were actually the will of Pope Sergius III or if they were really the desire of Theophylact. Many accounts suggest that Theophylact was the real person in power and made Sergius follow his agenda. To be sure, Sergius did use his time as Pope to place many of his family members and members of his aristocratic party to high positions within the Church.
Along with those scandals, Pope Sergius III did engage in the usual sort of scandal, namely that of a sexual nature. He was said to be in a relationship with Marozia, the teenage daughter of Theophylact. Some accounts claim that he fathered a child by her who later became Pope John XI. There is debate on who John’s father was because he was born after Marozia was married to Alberic I of Spoleto. But there are some who claim the child was the son of Sergius and that Alberic I knew his eldest son was illegitimate.