The Congiura dei Pazzi, or Pazzi Conspiracy, is a bloody and dramatic moment in Florence’s history. The day when an attack on the Medici brothers left Giuliano de’ Medici dying on the floor of Florence’s Cathedral.

Date: Easter morning, 26 April 1478 – Location: Florence’s Cathedral

But who were the participants in the Pazzi Conspiracy? And why did they want to kill the Medici brothers Lorenzo and Giuliano?

Loved, admired and celebrated by many of their fellow Florentine citizens, the Medici golden boys had their enemies too. A multitude of political rivals, inside and outside Florence opposed their growing power. The ancient Florentine Pazzi family was one of them, and eventually drew together the other anti-medici factions under their banner. Even the Pope himself was against them.

Pazzi Conspiracy – Who did what, and why?

From the time of Cosimo the Elder (1389-1464), the grandfather of Lorenzo the Magnificent, the Medici were the unofficial rulers of Florence. The city was still a Republic, but one steered by the whims of its most influential families. As Guicciardini wrote, Lorenzo the Magnificent (1449-1492) was a kind of ‘delightful tyrant“. Not someone who was idealistically defending democracy in his city, but instead using all his money and influence to keep the position of power his family has built for itself.

lorenzo the magnificent facts
Giuliano de’ Medici (left) and Lorenzo the Magnificent (right)

The prestigious and wealthy Pazzi family found a perfect ally in Pope Sisto IV. He hated the Medici after they had tried to stop his expansion plans in central Italy, and he had revoked the Papal banking contract with the Medici bank.

The ‘unholy’ Pope Sisto IV had, in fact, wanted to buy the city of Imola to give to his nephew Girolamo Riario. When the Medici opposed him, he was more than happy to back up Riario, who was plotting a murderous plan with the anti-medici families in Florence.

Another shady clergyman got involved too, Francesco Salviati, who was related to the Pazzi and the Riario family. He had his own reasons for hating the Medici, as Lorenzo had stopped him from becoming Archbishop of Florence in 1474. The Pope proclaimed him Archbishop of Pisa, and he took an active role in the conspiracy. A few Italian rulers, like the Duke of Urbino and the king of Naples, also wanted the Medici gone, hoping that Florence would lose its favourable position in Italy.

The first attempt – a poisoned banquet

Riario struck a deal with Salviati, the Pazzi and their followers, with the Pope’s full collaboration. Then the conspiracy began to take shape.

Lorenzo and Giuliano needed to be murdered at the same time, so as to eliminate any chance of later revenge. So the first plan was to poison the two brothers during a banquet organised in Florence on 25th April 1478 to celebrate the young Cardinal Raffaele Riario, coming from Rome accompanied by Salviati.

But Giuliano was unwell that day and didn’t attend the party, so the murder was postponed until the following day. In the meantime, troops were ready to intervene in Florence and to occupy the key territories of the Florentine republic. Archbishop Salviati was supposed to take over Palazzo Vecchio, the seat of government.

Murder in Florence’s Cathedral

It’s Easter on 26th April 1478, a beautiful Sunday morning in Florence. The cathedral is slowly filling with people, while the plotters are ready to strike.

Lorenzo and Giuliano are attending Mass, and the murderers are waiting for the signal. As the host is raised heavenward, the two brothers are attacked.

Lorenzo reacts swiftly against his attackers, the two priests clearly not very good with swords, and manages to escape into the sacristy. Giuliano is less lucky. He’s brutally stabbed by Francesco de’ Pazzi with no less than 19 wounds. Blood stains the floor of Santa Maria del Fiore Cathedral.

Blood has been spilled but the coup has missed its mark. News of the crime spread quickly all over Florence, and the Medici friends and their followers go on the hunt for the guilty party.

Pazzi Conspiracy
The Pazzi Conspiracy – painting by Stefano Ussi

Revenge is served

Jacopo de’ Pazzi, who was brought back to Florence after trying to escape to the Apennines, is taken as a prisoner, and hanged from one of Palazzo Vecchio’s windows. The same fate was to befall Francesco de’ Pazzi, his cousin Renato, and Salviati. And by the end the entire Pazzi family was dealt with, the majority killed, and the rest imprisoned or exiled.

Even Guglielmo de’ Pazzi, husband of Lorenzo’s sister Bianca – a marriage that was supposed to make the two families united and peaceful – was condemned to lifelong exile. The memory of the Pazzi was erased from the annals of Florence, their property confiscated and their coats of arms removed.

Giuliano was buried and mourned, while Lorenzo emerged from the Pazzi conspiracy with reinforced power and prestige. Known as “the Magnificent” he had no official title in the Republic, and yet remained its leader until his death in 1492.

pazzi conspiracy
Pazzi Chapel, Church of Santa Croce

DID YOU KNOW? The second season of the Medici series, “Medici: the Magnificent”, was released on Netflix early in 2019. It focuses – but it’s not entirely historically accurate – on the facts that lead to the Pazzi Conspiracy.

Learn more about the life of Giuliano de’ Medici, the victim of the Pazzi Conspiracy.

florence history museums
Palazzo Vecchio, Florence