Origin of the animosity between Sixtus IV. and Lorenzo de' Medici --Carlo di Braccio da Perugia attacks the Siennese--Carlo retires by desire of the Florentines--Conspiracy against Galeazzo, duke of Milan--His vices--He is slain by the conspirators--Their deaths.
The pope, anxious to retain the territories of the church in obedience, had caused Spoleto to be sacked for having, through internal factions, fallen into rebellion. Citta di Castello being in the same state of contumacy, he besieged that place; and Niccolo Vitelli its prince, being on intimate terms with Lorenzo de' Medici, obtained assistance from him, which, though inadequate, was quite enough to originate that enmity between Sixtus IV. and the Medici afterward productive of such unhappy results. Nor would this have been so long in development had not the death of Frate Piero, cardinal of St. Sixtus, taken place; who, after having traveled over Italy and visited Venice and Milan (under the pretense of doing honor to the marriage of Ercole, marquis of Ferrara), went about sounding the minds of the princes, to learn how they were disposed toward the Florentines. But upon his return he died, not without suspicion of having been poisoned by the Venetians, who found they would have reason to fear Sixtus if he were allowed to avail himself of the talents and exertions of Frate Piero. Although of very low extraction, and meanly brought up within the walls of a convent, he had no sooner attained the distinction of the scarlet hat, than he exhibited such inordinate pride and ambition, that the pontificate seemed too little for him, and he gave a feast in Rome which would have seemed extraordinary even for a king, the expense exceeding twenty thousand florins. Deprived of this minister, the designs of Sixtus proceeded with less promptitude. The Florentines, the duke, and the Venetians having renewed their league, and allowed the pope and the king to join them if they thought proper, the two latter also entered into a league, reserving an opening for the others if they were desirous to become parties to it. Italy was thus divided in two factions; for circumstances daily arose which occasioned ill feeling between the two leagues; as occurred with respect to the island of Cyprus, to which Ferrando laid claim, and the Venetians occupied. Thus the pope and the king became more closely united. Federigo, prince of Urbino, was at this time one of the first generals of Italy; and had long served the Florentines. In order, if possible, to deprive the hostile league of their captain, the pope advised, and the king requested him to pay a visit to them. To the surprise and displeasure of the Florentines, Federigo complied; for they thought the same fate awaited him as had befallen Niccolo Piccinino. However, the result was quite different;for he returned from Naples and Rome greatly honored, and with the appointment of general to their forces. They also endeavored to gain over to their interest the lords of Romagna and the Siennese, that they might more easily injure the Florentines, who, becoming aware of these things, used their utmost endeavors to defend themselves against the ambition of their enemies; and having lost Federigo d'Urbino, they engaged Roberto da Rimino in his place, renewed the league with the Perugini and formed one with the prince of Faenza. The pope and the king assigned, as the reasons of their animosity against the Florentines, that they wished to withdraw them from the Venetian alliance, and associate them with their own league; for the pope did not think the church could maintain her reputation, nor the Count Girolamo retain the states of Romagna, while the Florentines and the Venetians remained united. The Florentines conjectured their design was to set them at enmity with the Venetians, not so much for the sake of gaining their friendship as to be able the more easily to injure them. Two years passed away in these jealousies and discontents before any disturbance broke out; but the first which occurred, and that but trivial, took place in Tuscany.
