Despite this, Kunigunde's brother, Wenceslaus married Hertmann's sister, Judith of Habsburg in 1285.

Kunigunde's sister Agnes followed suit and married Rudolf II, Duke of Austria, brother of Hartmann.

A substantial amount of Polish nobles and citizens wished for Władysław I the Elbow-high to become King of Poland.

Wenceslaus needed help to keep Poland so he decided to marry Kunigunde off to Boleslaus which would create a firm alliance with a powerful Polish noble.

In retaliation, Boleslaw withdrew his support for Wenceslaus' rule in Poland and sent Kunigunde back to Prague.

Wenceslaus II had married Elizabeth Richeza of Poland after the death of Judith of Habsburg, to create an alliance with some Polish nobles, remedying the loss of Boleslaw's support.

Kunigunde fostered her niece, the orphaned Elizabeth of Bohemia, who went to live with her in the Monastery of St. George.