Bianca Capello (born 1548, Venice [Italy]—died Oct. 20, 1587, Poggio, near Florence) was a Venetian noblewoman, renowned for her beauty and intelligence, whose court intrigues were the scandal of her time.
Against the will of her family, Bianca ran off and married a young Florentine named Pietro Buonaventuri. She soon became the mistress of Francesco I de’ Medici, at first secretly and then openly after the murder of her husband (1569). She succeeded in marrying Francesco (1578) by means of a bizarre plot in which she feigned a pregnancy and presented him the baby of a common woman as her own son.
Her conduct and machinations aroused much enmity at the Florentine court, especially that of the powerful Cardinal Ferdinando I de’ Medici, brother of Francesco. Bianca and Francesco fell ill at Poggio and died within a day of each other; they may have been poisoned with the consent of Ferdinando.