Unlike his brother Władysław, who was allied with Bohemia, Bolesław II maintained close ties mainly with the Kingdom of Poland.

In 1443 he supported Poland in his conflicts with Hungary, and in 1449 he was appointed judge in the disputes between King Casimir IV and the Bohemian nobility.

However, Bolesław II's good relations with Poland didn't prevent the sale of the Duchy of Siewierz to Zbigniew Oleśnicki, Bishop of Kraków, which resulted in a war at Upper Silesia, who lasted until February 1447.

Bolesław II sought to obtain independent sovereignty, and therefore in 1452 he swapped with his brother Wenceslaus I the district of Bielsko for one half of Bytom, where he planned to settle.

The union had the approval of Anna's cousin, King Casimir IV, who give to the newlyweds a magnificent wedding gift: 2,000 florins.