17. Eugene IV bought his election on a grand style in 1431
Pope Gregory XII appointed his nephew as Bishop of Siena, an act which the local populace opposed since the nephew, Gabriele Condulmer, was from Venice, and only 24 years of age. Instead, Gabriele accepted an appointment as Cardinal Priest of the Basilica of San Clemente. When Pope Martin V died Gabriele offered the cardinals a contract which promised to deliver to their control one half of the money acquired by the church during his papacy in exchange for his election. Gabriele assumed the name Eugene IV, and immediately took steps to weaken the power and influence of the Colonna family, of which his immediate predecessor had been a member.
His papacy was marked by power struggles with the Councils of the Church, which the pope moved to dissolve and which resisted dissolution, gaining the support of the Holy Roman Empire. The Council of Constance declared the pope subservient to the council, and open warfare between the Papal States and their enemies plagued his reign. Eugene had his enemies which fell into his hands tortured and executed, frequently by burning. When Portuguese Prince Henry asked Eugene to designate the slave raids along the African coast a Holy Crusade, Eugene replied in a Papal Bull which offered remissions of sins for those taking part in the raids, declaring slave raids part of the extension of Christianity no different from the crusades against Islam.