The article reveals the study of the state affiliation issue of the Western Volyn territory in the concepts and practices of Polish political groups of the 19th‒20th century and their prominent ideologues. The revival of the Polish state was the only common political aim of the conceptual grounds of the leading Polish doctrines of incorporation and federalism. Nevertheless, practical methods and ways of realising the set objectives of the concepts mentioned above in the geopolitical dimension differed significantly. The nationalist views of the Polish politician R. Dmowski formed the basis of an incorporative political program, which stipulated the restoration of an independent Polish state within the borders of 1772 with the inclusion of Ukrainian lands – Volyn territory. The political beliefs of the Polish national leader J. Piłsudski were based on the concept of a federal union of Poland, Lithuania, Belarus, and Ukraine, which in turn considered the revival of the historical tradition of state‒building. According to this concept, Western Volyn should have belonged to Poland. Analysing the evolution of the concepts mentioned above in terms of historical events of the 19th and 20th centuries and their content related to Ukrainian issues, the author highlights that the western Ukrainian lands, in particular, Western Volyn, were accepted exclusively as Polish and a priori should have been the territory of the restored Polish state. The formation of the “illusory image” of Volyn as a Polish territory directly impacted the region’s further development. In particular, it influenced the relations between the neighbouring peoples ‒ Poles and Ukrainians. The establishment of official diplomatic relations between Poland and soviet russia, outlined in the Treaty Riga 1921, marked the victory of “incorporated” views over federal ideas. Meanwhile, the threat of expansion from the russian Bolsheviks contributed to the emergence of the Promethean political doctrine. Creating an independent Ukrainian state was one of the crucial elements aimed at functioning as a buffer zone between Poland and the Soviet Union. At the same time, the territory of Western Volyn was supposed to belong to Poland.