This contribution to the discussion about the continuity of Russian (or Soviet) history focuses on the transformation of Roman Catholic Church in Russia (or the Soviet Union) before the October Revolution of 1917 and in the era that followed. It is based mainly on the knowledge of Vatican Archives and published primary sources which are then confronted with a wide array of secondary sources, mainly of British and Italian origin, summarizing the topic from the viewpoint of Western historiography. Although lacking the accent on Russian sources, it is focused on the political and religious situation in Russia in the time since the turn of the 19th and 20th century until 1920s, as seen by the Holy See. The article introduces the reader to the religious life in the country – with a further focus on Roman Catholic Church and its prominent dignitaries and personas – while taking into account the transformation of the Catholic Church in the first decade of the 20th century that has seen the Holy See hoping to be able to convert Russia to Catholicism. It also explains the animosity of Russians towards the Roman Catholicism which escalated in physical elimination of its officials in the 1920s, followed by effective elimination of the Church as a whole in 1930s.