With respect to the Grand Duchess Giovanna and her detestation of Bianca, a story may be told which has all the appearance at least of probability. Giovanna expressed, not once, but often, her wish for Bianca’s death. This, indeed, in those days, and in Florence, the “City of Assassins,” was as good as a judicial sentence. The Grand Duchess, moreover, it was reputed, followed up her words by action. “One day,” the story goes, “in the month of March 1576, her carriage chanced to meet that of Bianca’s upon the Ponte SS. Trinita. She besought her coachman to try and upset her rival, hoping that she might fall into the river below and be drowned! Conte Eliodoro del Castello, her Chamberlain, saw the manoeuvre and prevented a deplorable fatality.”
Be this as it may, the Grand Duke not only sympathised with Bianca’s fears, but appointed certain of his own bodyguard to take up similar duties near the person of Madonna Buonaventuri, and her progresses henceforward were watched with as much circumstance as his own. At the same time his devotion to the woman he loved increased from day to day. The perils she was called upon to meet were incurred through her unquestioning love of him. This he knew well enough.
Writing on 29th March 1576, Carlo Zorzi, the Ambassador of the Serene Republic, and a warm adherent of his fascinating fellow-countrywoman, says: “I visited the Grand Duke’s Villa Pratolino, and also Madonna Bianca Buonaventuri’s charming retreat, the Orte Oricellari, and her pretty Villa della Tana, which he had lately given her, looking upon the Arno, and I observed Don Francesco’s intimacy with the Madonna. I noted also her extraordinary influence for good upon him.... They appear to be made for one another, and to be absorbed in the same occupations and interests.... She had but to name an object for charity or patronage, and at once she had his hearty approval.”
Francesco never concealed his concern at having no son. With his own physicians and the physicians of the Grand Duchess he held many consultations: not a few quacks and empirics also were sought to for nostrums and charms which should obtain by science what nature had so far withheld. He and Bianca held anxious counsel, for he knew that she would lay down her life for him, and would grant him every facility which it was in her loving power to supply.
Reflecting deeply, Bianca saw only one situation: Giovanna was barren of male issue, why should not she herself become once more a mother—the mother of a son, a son of Francesco!
This idea haunted her, but all the same she had no conception; and then a design presented itself to her weary brain—as natural as it was indefensible. For some time she had been getting stout—her age, her constitution, and her rich living were all conducive to that condition. If she was not to be the mother of his child by natural means, she could be so by a subterfuge, which her embonpoint would uphold!