The present study is a continuation of the dissertation entitled "The attitude of the German ecclesiastical authorities towards the Polish population in the diocese of Warmia", which covered the period from the beginning of the 19th century until the "Kulturkampf". The purpose of the study is to present the case of the Polish Catholic population in the Diocese of Warmia after 1870 against the background of the Prussian policy of Germanisation and the ecclesiastical rule of the bishops of Warmia. The study ends in 1914. This date is justified by the changes brought about by the First World War itself, the Treaty of Versailles, the plebiscite and post-war German policy, which created different living conditions for Poles in Prussia.