Catherine Jagiellon (Polish: Katarzyna Jagiellonka; Finnish: Katariina Jagellonica; Swedish: Katarina Jagellonica av Polen; November 1, 1526 - September 16, 1583) was Duchess of Finland 1562-83, Queen Consort of Sweden 1569-83 and Grand Duchess of Finland 1581-83 and heir to her mother's claim to the title of King of Jerusalem.
She was born as the youngest daughter of Poland's King Zygmunt I the Old and Bona SforzaCatherine became the wife of Sweden's King John III and mother to the future King of the Polish-Lithuanian Commonwealth, Sigismund III Vasa.
Bianca Maria Visconti, heiress of the Visconti dynasty, Duchess of Milan, Catherine's great-great-grandmother.
Catherine Jagiellon (Polish: Katarzyna Jagiellonka; Finnish: Katariina Jagellonica; November 1,1526 - September 16 1583) was the youngest daughter of Poland's King Zygmunt I the Old and Bona Sforza, heir to her mother's claim to the title of King of Jerusalem, Dutchess of Finland and later the Queen of Sweden.
Catherine became the wife of Sweden's King John III and mother to the future King of the Polish-Lithuanian Commonwealth, Zygmunt III Vasa.
On October 4, 1562, in Vilnius, Lithuania, Catherine married Duke John of Finland, second son of Sweden's King Gustav I.