Written by France 24

An assassination attempt on Pope Sixtus IV led to the excommunication of the House of Medici from the Catholic Church and the declaration of holy war on the city of Florence in 1478.

In a dramatic scene, the Pope was poisoned as he spoke to members of the Houses of Borgia and Medici, and quick medical assistance from an aide was able to save his life. The Pope immediately suspected the Medici family was behind the attempt and promptly excommunicated the family and declared war. The Pazzi family has already met his declaration of holy war on Florence with plans to invade Florence and take power back from the Medici family.


The House of Medici and the Catholic Church have had a contentious relationship for decades, due in part to the Borgia’s control of the institution. While the Medici provide funding for the church, the Borgia maintain intense influence and favor, having sworn a written oath of loyalty to Pope Sixtus IV and the Catholic Church. In the wake of the assassination attempt, Pope Sixtus IV has allied himself even more heavily with the House of Borgia.

Pope Sixtus IV’s alliance with the House of Borgia solidifies the strong relationship between the Catholic Church and the family, which produced Pope Callixtus III (formerly Alfonso de Borgia) in 1455. The relationship began with the influence of Alfonso de Borgia in ending the Papal Schism, as he convinced Pope Clement VIII to submit to Pope Martin V and reunify the church. For his efforts, de Borgia was granted the title of Bishop of Valencia and later elected to the papacy. Pope Callixtus III used his influence to provide key family members with church positions, including appointing nephew Rodrigo Borgia as Bishop of Valencia.

The Pazzi family plans to invade Florence within the next few days and has extended an offer to the House of Borgia to participate, supported by Pope Sixtus IV. Waluigi de Pazzi and Giovanni de Pazzi approached the House of Borgia shortly after the assassination attempt, promising assistance in the fight against the Medici in return for control of Florence upon its capture. The Pope supports the alliance: “Considering this house has sworn a written oath of loyalty,” he told them, “I’m sure this proposition will be easy to accept.”

The Borgia have yet to respond to the offer and are considering a potential counter-allegiance with France instead, though the majority appears to be in favor of allying with the Pazzi family. “Whatever we do as a House of Borgia should be in the name of the church, because we’ve sworn our allegiance to the church. Whatever we do should always be in the benefit of our family and of God,” said Pedro Luis de Borgia, Captain-General of the Catholic Church, in an interview. “I will be supporting whatever this committee does regardless of my personal opinion… The people like me. Whatever I say, the people will go with me.”


The House of Medici, by contrast, has struggled to respond to the threat of invasion. In a chaotic scene, members of the house argued with one another as they sought to consolidate troops to meet the Pazzi threat. “We should not use personal troops… this is not the time for your crisis arc,” one delegate said in frustration as others shouted to be heard.

The threat from the Pazzi family to the House of Medici is substantial, as the Pazzi previously allied with the Catholic Church in an unsuccessful attempt to remove the Medici from power in Florence. The unsuccessful coup led to the death of significant Pazzi family members and the removal of the Pazzi family from Florence entirely.