Abstract
The phenomenon of "secession", "secessionist movements" became a widespread concept after the Second World War. Accordingly, this phenomenon has been widely studied on the basis of an interdisciplinary approach. The purpose of this study is to systematize non-existent theories about secession by their content nature. Based on the results of this study, six theoretical groups were identified. Firstly, the secessionist movement can be explained by a moral and normative approach based on liberal criteria. Secondly, the secession can be explained on the basis of a political and economic approach in the context of the principle of "rich region" vs "poor region", according to which regions with backward potential will always be a "heavy burden" for regions with developed political and economic potential. Thirdly, the phenomenon of secession is characterized by criteria of economic efficiency and inefficiency based on economic rationality. Fourth, the emergence and development of secessionist movements occurs as a result of the influence of international systems and the intervention of external actors. Fifth, theories that consider the activities of political, economic, and religious institutions at the state and regional levels as the main factors explaining the emergence of secession. Sixth, theories that consider the phenomenon of secession as a result of strategic actions of ethnic minorities against the central government. Key words: secession, secessionist movements, secession formulation, sovereignty, territorial unity, conceptualization, ethnic conflicts