Like his father and his younger brother Vilém, Zikmund supported the Bohemian King George of Poděbrady.
This time, he was held by Zdeněk Konopišťský of Sternberg, the leader of the Zelená Hora Alliance at his residence in Polná.
They supported the newly elected king Vladislaus II of Bohemia and Hungary, who granted them certain rights over the monastery at Oslavany and the Porta coeli Convent at Tišnov in 1471 and 1472.
[1] Corvinus's advisor, the later bishop John Filipec, was committed to negotiating Zikmund's release.
In 1473, she remarried with Linhart of Guttenstein and Zubštejn fell back to her first father-in-law Jan II of Pernštejn.