Who married Francesco III. Gonzaga?

Francesco III. Gonzaga (* 10. März 1533 in Mantua; † 21. Februar 1550 ebenda) war von 1540 bis 1550 nominell Herzog von Mantua und Markgraf von Montferrat, gelangte jedoch nie zur selbständigen Regierung, da er bereits kurz vor seinem 17. Geburtstag starb.

Catherine of Austria (Polish: Katarzyna Habsburżanka; Lithuanian: Kotryna Habsburgaitė; 15 September 1533 – 28 February 1572) was one of the fifteen children of Ferdinand I, Holy Roman Emperor and Anna of Bohemia and Hungary. In 1553, she married Polish King and Lithuanian Grand Duke Sigismund II Augustus and became Queen consort of Poland and Grand Duchess consort of Lithuania. Their marriage was not happy and they had no children together. After a likely miscarriage in 1554 and a bout of illness in 1558, Sigismund became increasingly distant. He tried but failed to obtain a divorce from the pope. In 1565, Catherine returned to Austria and lived in Linz until her death. Sigismund died just a few months after her, bringing the male line of the Jagiellon dynasty to its end. The dynasty would continue, strictly speaking, for one more reign—that of Sigismund Augustus’ sister, Anna Jagiellon, who was crowned with the male title of Rex Poloniae.