Born in the old castle of Avigiana, Turin, Bona was a daughter of Louis, Duke of Savoy and Anne de Lusignan of Cyprus.

The revenge of the brothers-in-law, however, was not long in coming: helped by the leader Roberto Sanseverino, the young Sforza set up an army that invaded the Duchy, conquering Genoa and Tortona between 1478 and 1479.

It is not clear when the man became her lover, but after the death of Galeazzo Maria quickly acquired great power and enormous influence over Bona, thus becoming a personal enemy of Cicco.

[5] After the death of Sforza Maria, perhaps poisoned by Bona herself and Simonetta, Antonio Tassino persuaded his lover to grant his other brother-in-law, Ludovico, the return to Milan, in the hope that this would be enough to free him from the uncomfortable presence of Cicco.

She demanded to leave the duchy and return to Piedmont or France, where she had grown up, and threatened suicide when Ludovico and Roberto Sanseverino tried to prevent her, so that the two were forced to give in.

[8] Bona of Savoy commissioned the Sforza Book of Hours, which was painted in about 1490 by a famous court artist, Giovan Pietro Birago.