Henryk IV Probus
In 1276, Siewierz received city status. On 26 February 1289, in front of the city gates of Siewierz, the allied forces of Władysław I the Elbow-high, then Duke of Kujawy and Mazovia, the future King of Poland, defeated the army of Henryk IV Probus, duke of Wrocław and Kraków. Henryk IV Probus accepted vassalage and protection from the Bohemian king, Wenceslaus II. He was the first Piast Silesian duke to become Bohemian vassal, leading to Bohemian annexation of most Silesia in the coming years.