Duchy of Opole
In the 12th century, the castellany of Bytom, including the Chorzów area, belonged to the Seniorate Province (Kraków Duchy) of Poland. In 1179 it was awarded by Duke Casimir the Just to the Duke of Opole, and since that time the history of Chorzów has been connected to the history of Upper Silesia (Duchy of Opole).