It was settled that the time to strike at both brothers would be at the sounding of the sanctuary bell, presumably when it was rung at the elevation of the Host. This moment would be ideal, not only because the sound of the bell and the celebrant’s gesture would provide unmistakable signals which all the assassins would hear and see, but also because the eyes of the victims, and of the congregation generally, would be downcast in reverence when the first blows were struck. As soon as the murders had been committed, Archbishop Salviati and Jacopo di Poggio Bracciolini, the ambitious, extravagant, impoverished son of the humanist who had been Cosimo’s friend, together with a large party of armed supporters were to march upon the Palazzo della Signoria, seize the government and kill any of the Priori who might attempt to resist them.
Towards eleven o’clock on that Sunday morning, 26 April 1478, young Raffaele Riario rode into Florence from Montughi and dismounted in the cortile of the Medici Palace. He was taken upstairs to the apartments on the first floor which had been set aside for his use and there he changed into his cardinal’s vestments. When he was ready he went downstairs again where, at the foot of the staircase, he was met by Lorenzo who accompanied him to the Cathedral. On their way they were joined by Archbishop Salviati who did not, however, enter the building, excusing himself on the grounds that he had to go and see his mother who, so he said, was seriously ill. Lorenzo took the Cardinal up to the High Altar and left him there, walking across to a group of friends in the ambulatory. There were no chairs in the nave and the large congregation moved about freely.
Giuliano had not yet arrived, so Francesco de’ Pazzi and Baroncelli hurried back to the Medici Palace to fetch him. They discovered that he had decided not to go to Mass after all as his leg was still troubling him; but at length he was persuaded to change his mind, and he limped down the Via Larga towards the Cathedral. In the street Francesco de’ Pazzi threw his arm round him as though in playful affection, remarking that he seemed to have grown quite fat during his illness, squeezing his body to ensure that he wore no armour under his shirt. His fingers felt the unprotected flesh. He noticed also with relief that Giuliano wore no sword.
As they entered the Cathedral, Francesco de’ Pazzi and Baroncelli made for the northern side of the choir. Giuliano politely followed them. They stopped close to the door that leads out into the Via de’ Servi. Lorenzo was still standing in the ambulatory on the other side of the High Altar, beyond Ghiberti’s wooden screen which then separated it from the choir. His friend Poliziano was near him; so were four other friends, Filippo Strozzi, Antonio Ridolfi, Lorenzo Cavalcanti and Francesco Nori, formerly manager of the Medici bank in Lyons. The two priests, Maffei and Stefano, were immediately behind him.
At the sound of the sacristy bell, the priests snatched their daggers from their robes. Inexpertly, Maffei placed his hand on Lorenzo’s shoulder, as though to steady himself or to make sure of his aim. As Lorenzo turned, he felt the dagger’s point against his neck. Maffei lunged forward, and the tip of the dagger cut into the tensed flesh. Lorenzo leapt away, tearing off his cloak as he did so and wrapping it around his arm as a shield. He drew his sword, slashed at the two priests who, unnerved by his fast reaction, were beaten back without difficulty. Then he vaulted over the altar rail and dashed headlong for the new sacristy.
Giuliano’s mutilated body was already on the floor. At the sound of the sacristy bell he had dutifully lowered his head, and Baroncelli, crying out, ‘Take that, traitor!’, had brought his dagger down in a ferocious blow that almost split his skull in two. Francesco de’ Pazzi thereupon stabbed him with such frenzy, plunging the blade time and again into the unresisting body, that he even drove the point of the dagger through his own thigh. Giuliano fell to his knees while his two assailants continued to rain savage blows upon him, slashing and stabbing until the corpse was rent by nineteen wounds.
As Giuliano’s blood poured over the floor, Baroncelli leapt over the body and made for the new sacristy, striking down Francesco Nori whom he killed with a single blow, and wounding Lorenzo Cavalcanti in the arm. But before he could reach the heavy bronze doors of the sacristy Lorenzo had dashed through them, and Poliziano with some other of his friends, had managed to get them shut. ‘Giuliano? Is he safe?’ Lorenzo kept asking; but no one answered him. While Antonio Ridolfi sucked the wound in Lorenzo’s neck, in case the priests’ daggers had been poisoned, another friend, Sigismondo della Stufa, who had escaped with them into the sacristy, clambered up the ladder into della Robbia’s choir loft to look down into the Cathedral.
The congregation was in uproar. People were shouting that the dome had fallen in. Lorenzo’s brother-in-law, Guglielmo de’ Pazzi was loudly proclaiming his innocence. Giuliano still lay where he had fallen. Raffaele Riario stood transfixed, as though in shocked dismay, by the High Altar. The two priests who had attacked Lorenzo, together with Giuliano’s assassins, had all apparently escaped. Lorenzo was bustled away by his friends to the Medici Palace.
Meanwhile Archbishop Salviati and the other conspirators had gone as planned to the Palazzo della Signoria with their armed supporters, most of them villainous-looking mercenaries from Perugia disguised as his suite. Salviati informed the Gonfaloniere, Cesare Petrucci, that he had an urgent message for him from the Pope. Petrucci, who was in the middle of dinner, gave orders for the Archbishop and his attendants to be admitted. Salviati himself was shown into a reception room, while the Perugians were placed in nearby offices, the doors of which were closed behind them. The Archbishop’s other companions, including Jacopo di Poggio Bracciolini, were left outside in the corridor.
Having completed his dinner, Petrucci came out to receive Salviati who by now was so nervous he was trembling. The Archbishop delivered what he claimed to be the Pope’s message in a thick and mumbling voice, almost incoherently, changing colour alarmingly, and glancing round from time to time at the door. Petrucci, having listened to him for a few moments only, called out the guard, whereupon Salviati rushed from the room, shouting to his own men that the moment to strike had come. The response to his cries, however, were muffled shouts and hangings; for, on assuming office as Gonfaloniere, Petrucci had had the rooms of the Palazzo della Signoria fitted with special catches which could not be operated from the inside. The Perugians were, for the moment, effectively imprisoned.
As they hammered on the doors, Jacopo do Poggio Bracciolini rushed at the Gonfaloniere who caught him by the hair and threw him to the ground. Then, shouting for the Priori to follow him and for the Vacca to be tolled, the strong and energetic Gonfaloniere snatched up an iron cooking-spit as the nearest weapon to hand and rushed at the Archbishop and his companions who were quickly beaten to the ground. The notes of the great bell were by then booming through the city as the people poured into the Piazza. Members of the Pazzi family and small groups of their supporters rode up and down through the streets shouting, ‘Libertà Libertà! Popolo e Libertà! Abasso i Medici! Abasso le pallet Libertà! Libertà!’ But although some of the people in the crowd joined in these shouts, most of them responded insistently with,’ Vivano le palle! Vivano le palle! Palle! Palle! Palle!’