It was said that every man fell in love with her, and she, on her part, did not restrain her passion.  There was no one to advise, no one to check, no one to help her to keep in the path of wifely fidelity.  Reports of liaisons were made to the Duke by his Chamberlain from time to time, but these were couched in words which concealed his own part therein.  He and the Duchess were accustomed to be much alone together.  He was a musician and a linguist, a scholar and an artist like herself, and a most attractive companion.  She helped him in his great literary work—­Lezione della Lingua Toscana—­perhaps the only serious occupation she ever undertook.

An intimacy, with such a similarity of tastes, ripened naturally into a romantic attachment—­certainly quite in accord with the tenets of Platonic humanism, and perhaps something more!  That Duke Paolo was conversant with the relations of his wife with his cousin was well known, but he made no complaint, and took no action to check them.  Likely enough he had that “easy-going contempt of everything and everybody” which Niccolo Macchiavelli has stigmatised as the prevailing tone of Italian society.

Probably the sad deaths of Princess Maria and Duchess Lucrezia d’Este, and the tragic events in the Maremma of 1562, affected Isabella greatly, but they only tended to increase her husband’s detestation for everything Florentine.  No doubt he judged that Cosimo’s hand slew both Maria and Garzia—­might it not strike Isabella or himself!  When a man, in an autocratic position such as that made by Cosimo I., yields to unguarded passion, reason and right alike are at a discount.  Isabella’s husband had taken the measure of her father—­alas, that he was destined to follow his example!

For Isabella a new interest was created when, in 1564, Bianca Buonaventuri became “La cosa di Francesco,”—­her brother.  She, so to speak, clasped the lovely young Venetian to her bosom.  She entered into the romance of the elopement, and of her brother’s infatuation, with all her heart.  Isabella de’ Medici and Bianca Cappello-Buonaventuri became inseparable friends.

During Duchess Eleanora’s life the gaieties and the follies of the court had been kept within something like bounds, but she had hardly been laid in her tomb within San Lorenzo than Duke Cosimo gave reins to his passions, and the Palazzo Pitti and the various Medicean villas became the scenes of unbridled lust and depravity.  In 1564 the Duke deputed most of his sovereign power to his son Francesco, who became Regent and virtual ruler of Tuscany.

The grave scandals which distracted Florentine society began to raise up in the minds of the people violent antipathy for a Sovereign whose private example was so abominable, and whose discharge of public duties was so basely marked by turpitude.  A revolution of a drastic description seemed to be inevitable, and, really, Cosimo had no other course than abdication.