If Piero and his sons were unassuming citizens, Messer Andrea’s second son, Giacopo, was of a very different disposition.  A man of far greater ability and more vaulting ambition than his brother, he was looked upon as the head of the family.  In appearance he was prematurely old and withered up, with a pallid face and palsied frame, with great restless, staring eyes.  He perpetually tossed his head about from side to side, as though afflicted with St Vitus’ dance.  Giacopo was unmarried, a libertine, notorious as a gambler and a blasphemer, a spendthrift, and jealous—­beyond bounds—­of the popularity and pre-eminence of Piero and Lorenzo de’ Medici.  He was pointed at as the most immoral man in Florence.  In the year of Lorenzo’s succession to the place of Capo della Repubblica, he obtained by bribery the high office of Gonfaloniere di Giustizia as a set-off, but, by an inconsistency as unexpected as it was transparent, he accepted, on vacating office, a knighthood at the hands of his rival.

Cavaliere Giacopo’s relations with Lorenzo were fairly cordial, outwardly at least, for as late as 1474, when at Avignon, he wrote several letters to him, full of grateful expressions for favours received and of wishes for a continuance of a good understanding.  None of Cavaliere Giacopo’s illegitimate children arrived at maturity, and, on account of the failure of his elder brother’s sons to achieve distinction, the proud banner of the family was clutched by the hands of the four boys of the youngest of Messer Andrea’s sons—­Guglielmo, Antonio, Giovanni, and Francesco.  Their mother was Cosa degli Alessandri, a granddaughter of Alessandro degli Albizzi, who first adopted the new surname.

The brothers were very wealthy, they had amassed large fortunes in commerce, and their houses extended for a considerable distance along that most fashionable of streets—­the Borgo degli Albizzi.  The Palazzo de’ Pazzi doubtless was commenced by their grandfather, whose emblem—­a ship—­is among the architectural enrichments.  The building was finished by their uncle, Giacopo—­it is in the Via del Proconsolo.

As bankers, the Pazzi were noted for their enterprise generally, and for their competition with the Medici in particular.  They had agencies in all the chief cities of Europe and the East, but their reputation for avarice and sharp dealing was proverbial.  Perhaps no family was quite so unpopular in Florence.  Their traditions were aristocratic, whilst the Medici were champions of the people.

This distinction was referred to by Madonna Alessandra Macinghi di Matteo degli Strozzi, in one of her letters to her son Filippo, at Naples.  “I must bid you remember,” she wrote, “that those who are upon the side of the Medici have always done well, whilst those who belong to the Pazzi, the contrary.  So I pray you be on your guard.”

The growing importance of the Pazzi gave Piero and Lucrezia de’ Medici much uneasiness, and it is quite certain that the marriage of their eldest daughter, Bianca—­“Piero’s tall daughter” as she was called—­to the eldest of the three brothers, was a stroke of domestic policy by way of controlling the race for wealth and power.