The situation became greatly embittered when, in 1477, Lorenzo interfered in a law-suit which concerned the marriage dower and inheritance of Beatrice, the daughter of Giovanni Buonromeo. By Florentine law the daughter should have inherited the fortune without demur, under the express will of her father, who died intestate; but, at Lorenzo’s command, the estate was passed on to Beatrice’s cousin, Carlo Buonromeo, who was the winner of the second prize in Lorenzo’s Giostra of 1468. This decision was in direct opposition to Giuliano de’ Medici’s opinion, and he did all he could to reassure Giovanni de’ Pazzi, Guglielmo’s brother, and Beatrice’s husband, of friendship and confidence.

These were not the only incidents which followed one another at the parting of the ways of the two families, but the affair of Giovanni and Beatrice was resented with peculiar bitterness by all the Pazzi. “Hence arose,” as Francesco de’ Guicciardini has testified, “the wronging of the Pazzi!”

In Francesco, the youngest of the brethren, was exhibited the most violent animosity and hatred. Blessed with superabundant self-conceit, which went so far as to cause him to spend hours a day having his unusually light-coloured hair dressed at the barber’s and his face salved and puffed at the apothecary’s to conceal his muddy complexion, he was reckoned, in the Mercato Nuovo, as little better than an ill-conditioned braggadoccio! His shortness of stature he sought to atone for by his accentuation of the Florentine pout and the Tuscan strut—he was well known, too, for his contemptuous jokes at the expense of others.

Francesco denounced Lorenzo and his Government with unmeasured scorn, and, careless of restraint, threatened that “he would be even with him, even though it cost him his life.” Macchiavelli says: “He was the most unscrupulous of his family.” “A man of blood,” Agnolo Poliziano called him, “who, when he meditated any design, went straight to his goal, regardless of morality, religion, reputation and consequences.”

Early in March he quitted Florence suddenly, giving out that his presence was required at Rome in connection with the affairs of the Pazzi bank. To say that his departure was a relief to Lorenzo is but half the truth, for he was greatly perturbed with respect to the influence which such a passionate and reckless rival would have upon his relations with the Holy See. Francesco was the subject of watchfulness upon the part of the Medici agents in Rome, where Giovanni de’ Tornabuoni set himself to thwart any hostile movement which might be made.

Among prominent men with whom Francesco de’ Pazzi was thrown into contact were Archbishop Francesco de’ Salviati and Count Girolamo de’ Riari. The Archbishop and Francesco were no strangers to one another; their families had risen to affluence and power side by side in Florence, actuated by like sentiments and engaged in like activities—hatred of the Medici was mutual.

Sixtus had proposed, in 1474, to bestow upon Francesco de’ Salviati the Archbishopric of Florence, but the Signoria, instigated by Lorenzo, refused to confirm his appointment and declined to grant him the temporalities of the See. The Pope yielded very ungraciously to the representations of the Florentine Government and named Rinaldo d’Orsini, Lorenzo’s brother-in-law, to the vacancy. This intervention was adduced by Sixtus afterwards as insubordination worthy of punishment, and he did not forget to take his revenge.

The following year Francesco de’ Salviati was chosen as Archbishop-designate of Pisa, and again the Florentines objected—being joined by the Pisans, who conspired to prevent him taking possession. The Archbishop was, according to Agnolo Poliziano—the devoted historian and poet-laureate of Lorenzo il Magnifico—“An ignorant man, a contemner of all law—human and divine—a man steeped in crime, and a disgrace to his family and the whole State.”

Count Girolamo de’ Riari, accounted a nephew of Sixtus, was, like his elder brother Piero and Caterina his sister, a natural child of the Pope. The three were treated with parental affection by the pontiff, and had their home in his private apartments, being waited upon by their unrecognised mother in the guise of nurse and guardian.

Piero de’ Riari was created a Cardinal when a spoilt boy, and became, as a man, infamous for his debauchery and villainy. Sixtus had the effrontery to select him as successor to Archbishop Orsini in Florence, but his action was prompted by a motive, which was firmly fixed in his heart. This was nothing less than the supplanting of Lorenzo de’ Medici by Piero or Girolamo! So far, however, as Cardinal de’ Riari was concerned, Sixtus’ ambitions were wholly disappointed by his sudden death, due to violent excesses of all kinds.