Francesco de' Pazzi and Count Girolamo Riario discuss the plot while Francesco is staying in Rome, they eventually get the pope to support their attempt. Raffaello de’ Riario had recently been elevated to the position of cardinal, so they used this as a pretext for going to Florence.
Salviati, Jacopo Pazzi, and Francesco Pazzi plan the conspiracy in Jacopo’s villa outside the city in Montugi.
Francesco and Salviati send Giovanni Battista to discuss with Lorenzo de' Medici to discuss the property of Carlo Manfredi, lord of Faenza, and then return to Florence to assist in convincing Jacopo de' Pazzi to join in the conspiracy.
They first planned to strike while Lorenzo and Giuliano were on the road to Piombino, but after that never materialized, they then planned to attack in Rome, which also never worked out.
The conspirators planned to attack them during a banquet in Fiesole, at the Medici villa outside the city. Lorenzo, Poliziano, and Lorenzo’s son Pietro all traveled there, but the attempt was postponed because Giuliano was ill and could not come.
After this, they settled for committing the murder during the high mass service in the Duomo of Florence.
While some conspirators committed the murder in the church, Francesco Salviati, Jacopo Braccolini, and the two Jacopo Salviatis, went to the Palazzo della Signoria as if to overthrow the residing Florentine lords and occupy the palace.
Stephano and Antonio de Volterra accepted the assignment to kill Lorenzo after Giovanni Battista had refused it. The rest of the conspirators were to attack Giuliano
When the conspirators arrived, Giuliano was still not present at the church, so Francesco de' Pazzi and Bernardo Bandini went to his house to convince him to attend. Through this, Francesco was also able to note that Giuliano was unarmed.
When the sound of the Elevation was heard, the conspirators made their move. Bernardo Bandini was the first to strike, stabbing Giuliano in the chest as Francesco de’ Pazzi and the other conspirators formed a circle around him. Francesco then stabs him with a dagger, repeatedly. During this frenzy, Francesco de' Pazzi stabs himself in the leg.
Giuliano received a sword wound to the head and was stabbed 19 times. He lay bleeding on the floor of the cathedral.
The assassins made to attack Lorenzo, then made their strike. Antonio da Volterra takes him by the left shoulder and tries to hit him in the throat. Lorenzo attempts to defend himself against the assassins, but is wounded in the neck and arm. Andrea and Lorenzo Cavalcanti, who served as escorts to Lorenzo, also come to his defense.
Lorenzo takes refuge in the Medici sacristy after the attempt.
Bandini makes an attempt to attack Lorenzo as well, as he makes is way to the sacristy, he stabs Francesco Nori, a Medici agent.
The doors to the Sacristy are closed and those inside (including Lorenzo and Poliziano, whose pamphlet is the main source used to chronicle this part of the conspiracy.) express concern over Giuliano and how he fared.
A group of Medici allies gathers outside the Sacristy, warning them to get out before the conspirators gained strength.
Sigismondo della Stufa sees Giuliano’s corpse, now knowing this, assures the people inside the Sacristy the crowd outside are allies.
Lorenzo and Poliziano are escorted home by the crowd, with them taking special care to keep Lorenzo from crossing paths with Giuliano’s corpse. Lorenzo did not find out about his brother’s death until hours later.
While the other conspirators attack in the church, Francesco Salviati (along with serveral Perugians whom he had recruited by making them promises he would help them retake their homeland) summons Cesare Petrucci, Gonfalonier of justice, while plotting to kill him. Petrucci suspects the plan and Salviati flees. Petrucci finds Jacopo Bracciolini, and injures him as he makes his escape. Salviati is eventually arrested and hung. Some of Salviati's retinue were thrown, alive, from the windows.
Jacopo de Pazzi attempts to rally public support, but is met with condemnation by the public. The people who had hidden out on top of the Palazzo throw javelins and stones at Jacopo, forcing him to take refuge with Francesco (the pamphlet does not specify which Francesco is referred to here), who had been seriously injured.
Lorenzo’s supporters hang Jacopo Bracciolini from a window.
Francesco Pazzi is hanged by the mob, not an hour after the conspiracy had begun.
Jacopo Pazzi flees the city, with a group of armed guards.
Antonio da Volterra and Stephano, who had attempted to attack Lorenzo, are both put to death.
The house of Francesco is looted, and Francesco de' Pazzi is led (already half dead) to be hung from the same window which Francesco Salviati was hung. The two Jacopos of the Salviati family were also executed in this same way.
Four days later, Jacopo and Renato de' Pazzi are executed. Jacopo is burried, dug up and dragged from there, buried along the walls of the city; and from there dug up again, he was dragged naked through the city by the noose with which he had been hanged; then, hid body was thrown into the Arno River.