Bona Sforza, Italian wife of Sigismund I the Old (born 1494)

Bona Sforza was Queen of Poland and Grand Duchess of Lithuania as the second wife of Sigismund the Old, and Duchess of Bari and Rossano by her own right. She was a surviving member of the powerful House of Sforza, which had ruled the Duchy of Milan since 1450.

Sigismund I the Old was King of Poland and Grand Duke of Lithuania from 1506 until his death in 1548. Sigismund I was a member of the Jagiellonian dynasty, the son of Casimir IV and younger brother of Kings John I Albert and Alexander I Jagiellon. He was nicknamed "the Old" in later historiography to distinguish him from his son and successor, Sigismund II Augustus. Before ascending to the Polish and Lithuanian thrones, he was Duke of Głogów from 1499, Duke of Opava from 1501, and governor of Silesia from 1504 on behalf of his brother, King Vladislaus II of Bohemia and Hungary.