The purpose of the study is to identify and analyze the main historical narratives of the Russian Orthodox Church (ROC), to fi nd out the interpretations of Ukrainian history as the ideological basis of Russian geopolitics of the integration of the post-Soviet space and the incorporation of Ukraine, to show the use of the historical policy of the ROC as an argument for the legitimization of the war against Ukraine. Th e methodological foundation of the research is the principles of objectivity, historicism, systematicity, and comprehensiveness. The methods of analysis and synthesis as well as problem-chronological, historical-genetic, and historical- comparative methods have been used. Th e scientifi c novelty lies in the fact that, for the fi rst time, the article examines the problem of the Russian Orthodox Church’s use of historical policy to form an ideological basis for the implementation of the neo-imperial geopolitical doctrine of the absorption of Ukraine by Russia. Conclusions. Th e ideologues of the original “Russian civilization” and “Russian world” are used as the theoretical foundation of Russian foreign policy towards Ukraine and as a rationale for the current geopolitical confrontation with the Western world. Th e historical policy of the Russian Orthodox Church is based on the promotion of the interconnected concepts of “Holy Rus”, “historical Rus”, and “historical Russia”, which imply the large civilizational space of the “Russian world”, of which Ukraine is an integral part. Th e importance of Ukraine in the historiosophical constructions of the Russian Orthodox Church is determined by the fact that the origins of Russian Orthodox spirituality and statehood are connected with the territory of modern Ukraine. Therefore, together with the Kremlin, the Russian Orthodox Church implements the neo-imperial geopolitical project of “the Russkiy Mir (“the Russian World”), aimed at restoring the Russian superpower and integrating the post-So- viet space”. Its ideological foundation is the historical-religious concept of “Holy Russia”, which implies the absorption of Ukraine by Russia. The claims of the Russian Orthodox Church about the entry of Ukraine into “historical Rus” and, accordingly, into “historical Russia”, the statements about one people, one faith, and a common state, insisting on the canonicality of the Russian Orthodox Church over the terri- tory of Ukraine – all these are the basis of the justifi cation that denies the separate identity of Ukrainians, the legitimacy of the autocephaly of the Orthodox Church of Ukraine, the right to the existence of the Ukrainian state and gives reasons to assert that the common past determines the common future. These arguments have become the rationale for Russian geopolitical expan- sion and aggression against Ukraine.