カジミェシュ2世
The Duchy of Bytom () or Duchy of Beuthen () was one of many Silesian duchies. It was established in Upper Silesia about 1281 during the division of the Duchy of Opole and Racibórz among the sons of Duke Władysław Opolski. The duchy's capital was Bytom ("Beuthen"), formerly part of Lesser Poland until in 1177 the Polish High Duke Casimir II the Just had attached it to the Silesian Duchy of Racibórz.