Having settled Girolamo comfortably at Imola, the Pope now turned his attention to another nephew, Giovanni della Rovere, who, although Prefect of Rome and Lord of Mondovi in Piedmont, was still anxious to get the same sort of foothold in the Romagna as his cousin had done. Sixtus obligingly fixed this for him by arranging a marriage with the eldest daughter of Duke Federigo of Urbino, which not only brought the territorial influence of the Pope closer than ever to the Florentine frontier, but also detached a highly successful condottiere from Florentine service.
By now, relations between Lorenzo and the Curia were growing excessively strained; and when the Pope endeavoured to dislodge Niccolö Vitelli from Città di Castello, a town near the Florentine outpost of Borgo San Sepolcro – which had been bought in Cosimo’s day with funds confiscated from a Jewish pawnbroker – Florence and the Papacy came close to war. Lorenzo raised 6,000 men to help defend Vitelli, which the Pope considered the grossest effrontery; and after Vitelli, despite this assistance, had been forced to surrender, he was given an honourable welcome in Florence, which antagonized Sixtus even more.
There was yet further trouble in 1474 when Piero Riario died, worn out by his relentless enjoyment of the rich benefices his uncle had bestowed upon him; and the Archbishopric of Florence became vacant once more. Lorenzo succeeded in having his brother-in-law, Rinaldo Orsini, appointed Riario’s successor; but he could not prevent the Pope nominating Francesco Salviati as Archbishop of Pisa, even though an undertaking had been given that no appointments to ecclesiastical benefices within the Republic should be made without the agreement of the Signoria. Since the Pope chose to ignore this undertaking, Lorenzo declined to admit Salviati into Tuscany; and for three years Salviati was kept waiting in Rome, frustrated, embittered and ready to lend his support to any anti-Medicean plot which might be proposed to him.
Lorenzo had other dangerous enemies in Rome. In order to maintain the uncertain peace in north Italy, he had proposed a mutual alliance between Florence, Milan and Venice. But, far from achieving peace, the proposal almost provoked another war, for the Pope angrily condemned the new league as aimed at himself, while King Ferrante of Naples was deeply suspicious of an alliance which had been formed without his being consulted and which seemed to threaten his interests in the Adriatic. The Pope and the King of Naples, whose traditional antagonism to the Papacy had been noticeably softened by the marriage of one of King Ferrante’s illegitimate daughters to Leonardo della Rovere – another nephew from the Pope’s seemingly inexhaustible supply – were now thrown closer than ever together in mutual distrust of the young upstart from Florence.
Lorenzo’s difficulties were made all the more complicated when, on St Stephen’s Day, 1476, his firm ally, Galeazzo Maria Sforza, was stabbed to death by three young assassins on his way to Mass. For Galeazzo Maria’s son was a small boy of seven. His mother declared herself Regent; but a disorderly gaggle of uncles clamoured for their brother’s succession. And until their quarrel was settled, Lorenzo could hope for no help from Milan against the conspirators now gathering to destroy him.
Three of these conspirators met in Rome during the early weeks of the new year, 1477. They were Girolamo Riario, whose ambitions were far from satisfied by the lordship of Imola; Francesco Salviati, the disgruntled Archbishop-designate of Pisa, who hoped to obtain the more distinguished Archbishopric of Florence; and Francesco de’ Pazzi, manager of the Pazzi family bank in Rome, a small, fidgety young man of’great arrogance and pretensions’, who thought that the time had now come for the Pazzi to take over as rulers of Florence from the Medici.
The Pazzi were a much older family than the Medici.1 One of their forebears, Pazzo de’ Pazzi, had been on the First Crusade and had returned to Florence with some flints from the altar of the Holy Sepulchre at Jerusalem which were deposited in the church of Sant’ Apostoli.2 They had loftily scorned trade up till the beginning of the thirteenth century; but in 1342 they had renounced their ancient lineage so as to be declared popolani and thus render themselves qualified for government office. They had subsequently made a fortune in banking. The head of the family in the early fifteenth century was Andrea de’ Pazzi who spent a sizable part of that fortune in commissioning Brunelleschi to build the Pazzi Chapel next to Santa Croce.3 His son, Piero, spent a good deal more of it on a fine library. But Piero’s brother, Jacopo, who succeeded him in 1464, was not so concerned to spend money as to conserve it.
Indeed, Jacopo was a tight-fisted old man, noted throughout Florence for his passion for gambling, and for losing his temper when he did not win. He thought the chances of a successful coup d’état were so slight that he was ‘colder than ice’ when his young relative, Francesco, apprised him of the plot being hatched in Rome. Besides, Guglielmo, one of his ten nephews, was Lorenzo’s brother-in-law, and he himself was on good terms with the Medici, even though Lorenzo’s rule threatened to continue to exclude his family from any real authority in the State. To be sure, like the rest of his family, he had been extremely annoyed when Lorenzo interfered in the matter of Giovanni Borromeo’s fortune. A Pazzi had married a daughter of this Borromeo and had naturally expected to inherit at least a good part of her family’s money; but when the father died a new law was passed – supposedly at the instigation of the Medici – which enabled his estate to pass to his nephews, who were known to be Medici supporters, rather than to his daughter and her husband, who were not. But Jacopo de’ Pazzi did not consider the Borromeo affair sufficient grounds for taking the inordinate risks involved in staging a coup d’état.
Supposing, however, that if he could produce evidence of strong military support the old man might yet be won over, Francesco de’ Pazzi now approached Gian Battista da Montesecco, a condottiere who had done good work in the past in the service of the Curia. Montesecco, a rough soldier not given to intrigue, was not immediately forthcoming. He explained that he was employed by the Pope and his nephew, Girolamo Riario, lord of Imola, and could do nothing without their blessing. Francesco reassured him that it was in the very interests of the Pope that he was acting; as for Girolamo Riario, he was a party to the plot; so was Francesco Salviati, Archbishop of Pisa. Montesecco was still not convinced, neither that day, nor on a later occasion when both Francesco de’ Pazzi and Salviati pressed their arguments upon him again, assuring him that Lorenzo had behaved abominably towards the Pope, that Girolamo Riario’s rule in Imola was ‘not worth a bean’ so long as Lorenzo lived, that the Medici rule was detested by the Florentines who would rise up in arms against their present rulers at the slightest encouragement.