Another grievance Sixtus had against Florence was the indirect aid given to Niccolò Vitelli, who had taken the side of Todi and Spoleto when they rose against the Pope, by despatching troops to Borgo San Sepolcro when the Cardinal Giuliano della Rovere laid siege to Città di Castello. The appointment of the anti-Medicean Francesco Salviati, as Archbishop of Pisa in the place of the late Filippo de’ Medici, in spite of a previous promise that no archbishop or bishop should be appointed within Florentine territory save by the consent of the Signory of Florence, was deeply resented by Lorenzo. Though unable to prevent the nomination he succeeded in keeping Salviati out of his archbishopric and consequently without his emoluments for three years. In 1477 the Pope’s anger against Lorenzo rose to fever-heat. He suspected, unjustly as it appears, that Florence had aided Carlo Fortebraccio in his endeavour to seize Perugia. The attempt failed and Fortebraccio overran the territory of Siena, which at once appealed to the Pope and the King of Naples, at the same time arrogantly summoning Florence to immediately recall the condottiere. Fortebraccio was in Venetian service, so the Florentines answered that they had nothing to do with him and only wished he would keep quiet. The murder of Galeazzo Sforza, Duke of Milan, had further complicated matters. Girolamo Riario was astute enough to realise that if the Pope died, the change of government in Milan might expose him to the resentment of Florence, and determined to try and overthrow the Medici. Francesco de’ Pazzi and Archbishop Salviati were easily persuaded to join, but shrewd old Jacopo de’ Pazzi, who lived in Florence and knew the hold the Medici had over the people, gave them no encouragement. Promises of foreign aid and the assurance of the assent of the Pope however at last won him over. An Abruzzese, Giovan Battista da Montesecco, a captain in the service of Girolamo Riario, was selected as a man to be trusted; his confession[212] is curious reading but too long to give _in extenso_. When he met Francesco de’ Pazzi in the Archbishop Salviati’s house at Rome he expressed grave doubts. “Have a care, gentlemen, what you are undertaking. Florence is no small matter, and Lorenzo, I hear, is very popular.” The Archbishop answered that they knew better how it stood with Lorenzo, that it was their affair and he was only the instrument. Montesecco then asked what the Pope would say, and was assured he hated Lorenzo and would follow their advice. Moreover he would receive the captain. Plans were then discussed. It was arranged that troops were to be held in readiness by Giovanni Francesco da Tolentino from Imola, Lorenzo Giustini from Città di Castello, and Napoleone Orsini from Todi and Perugia, to enter Florence as soon as the assassins had done their work. Soon afterwards Montesecco was summoned to the Vatican. “I will have no bloodshed,”