I'll present the core findings of an ongoing doctoral research project at KU Leuven addressing a fundamental lacuna in the study of Old Believer eschatology: the absence of a precise definition of the Antichrist in the tradition's own writings from the Schism of 1666 to the mid-19th century As early as the 1860s, Vasily Kel'siev noted the difficulty in grasping the core message of the Old Believers, precisely because their method was descriptive rather than definitional. While later scholarship, notably Robert O. Crummey, has rightly emphasized the need to analyze not only Old Believer texts but also their behavior as complementary data, the task of formulating a systematic definition of the Antichrist from this rich but diffuse material remains undone. The research employs a dual methodological framework. First, an inductive approach analyzes the vast corpus of Old Believer descriptions of the Antichrist—moving from the particular to the general—to extract essential, recurring elements. Second, an associative historical method treats the community's collective behavior—self-immolations, flight to forests, rejection of state documents—as a further layer of data to be interpreted. The study's central thesis is that before 1862, the foundational assertion was that the Antichrist had already come and was reigning. Subsequent distinctions (sensual, spiritual, dismembered Antichrist) were defense mechanisms protecting this core belief. Applying the associative method reveals a striking parallel: Old Believer behavior mirrors that of the Russian population under foreign occupations. Thus, the reigning Antichrist was conceptually identical to an illegitimate occupying authority—physically present, demanding submission, yet lacking spiritual or moral legitimacy. This definition offers a new lens for understanding Russian eschatology and apocalyptic political resistance, engaging directly with the panel's interest in peace and conflicts in memory and identity constructions.