On 7 November 1922, Bertram lost his episcopal competence in the parishes of Breslau diocese that had become part of Poland, namely in the prior Austro-Hungarian, now Polish eastern Cieszyn Silesia (Polish acquired 1918/1919), and the prior German East Upper Silesia (seized by Poland on 20 June 1922). On 17 December the Holy See established for these areas an exempt Apostolic Administration, which it elevated as the new Diocese of Katowice on 28 October 1925 by the bull Vixdum Poloniae Unitas. The parishes in northwesterly Czechoslovak Cieszyn Silesia (Zaolzie) remained under Bertram's jurisdiction of Breslau.