Transformation of the confessional structure of the population of Northwest Russia and the Baltics (late 19th — first quarter of the 21st centuries)

The secularization processes that have unfolded since the early 20th century have profoundly transformed the traditional religious structure of populations in many countries and regions. This study aims to trace the shifts in the confessional composition of the population in Northwest Russia, Estonia, Latvia, and Lithuania from the late 19th century to the present. The analysis is based on data from the 1897 and 2021 population censuses, as well as sociological surveys that included questions on religious affiliation. Drawing on the dynamics of confessional change, the study identifies 24 historical-confessional districts across Northwest Russia and the Baltics States. A typology of these districts is developed according to two principal criteria: the degree of complexity in the confessional structure and the changing proportions of the region’s four major religious groups — Protestants, Catholics, Eastern Christians, and Jews. The first type of district is characterized by a homogenization of the religious population in favour of Orthodox and Catholic groups, accompanied by a general heterogenization of the broader confessional structure, including the non-religious population. This type encompasses all districts of Northwest Russia, Ida-Virumaa County in Estonia, Latgale in Latvia, and parts of Lithuania. The second type, most extensively represented in Estonia and Latvia, exhibits heterogenization in both the overall confessional structure and its religious component. The third type is marked by the homogenization of the general confessional structure, with a predominance of Catholics in Lithuania, and of Protestants and the non-religious population in southwestern Estonia.