The article gives an overview of the history of the Diocese of Katowice. It begins by describing the situation in Upper Silesia after the First World War and the problems connected with the plebiscite. Then the functioning of the episcopal delegation and the apostolic administration is discussed. The activities of the prince-bishop's general vicariate in Cieszyn are also presented. Finally, the history of the Diocese of Katowice during the occupation and in the post-war period is presented.