Documentary Heritage of the Russian-Kazakh Border' History of the Formation: Systematization and Review of Russian Archival Funds

Introduction. The history of the formation of the state border between the Russian Federation and the Republic of Kazakhstan is a complex and lengthy process that reflects the political, administrative, and socio-economic transformations in the region. Throughout the twentieth century, the border was repeatedly clarified and adjusted due to the need for the rational use of territories and their economic potential within the framework of the union republics. Administrative delineation was carried out primarily in accordance with the internal development needs of the constituent entities of the Union. After the dissolution of the USSR, the issue of the legal consolidation and international recognition of the state border became particularly relevant. As a result of intergovernmental negotiations, in 2005 the Treaty on the Delimitation of the Kazakhstan — Russia Border was signed, which finally defined its legal status and spatial parameters.
Materials and methods. The main materials for studying the Kazakh-Russian border were documents located in: the Russian State Historical Archive, he Russian State Archive of Ancient Acts, the State Archive of the Russian Federation, as well as in departmental archives: The Archive of Foreign Policy of the Russian Empire of the Ministry of Foreign Affairs of the Russian Federation Ministry, in the archives of individual institutions: Archive of the St. Petersburg Institute of History of the Russian Academy of Sciences. When studying the archives, the following methods were used: source analysis — providing an analysis of documents; historical — allowing an objective assessment of the content of documents based on the historical conditions of their creation; historical-comparative for classifying documents by establishing their relationships; the method of source analysis, which allows to study the authorship and origin of documents.
Results. The analysis of archival collections devoted to the formation of the Kazakhstan-Russia border has made it possible to propose their systematization based on the principles of historicism and chronological sequencing. The archival materials are grouped into several categories: departmental collections containing documents of state bodies involved in defining and securing the border; personal archives of individuals who made a significant contribution to the process of territorial delimitation; and materials related to the history of the exploration of border regions and the activities of expeditions engaged in the description and cartographic delineation of boundaries. Particular attention is given to the Soviet period, during which the modern configuration of the Kazakhstan-Russia border was finally established.
Discussion. The process of the formation of the state border is viewed as an objective regularity that ensures the territorial integrity, sovereignty, and security of the state. For a comprehensive understanding of the development of the Kazakhstan — Russia border, it is essential to study the historical context as well as the socio-political factors that influenced the processes of delimitation and demarcation. The results of the archival analysis confirm that the territorial delineation in the twentieth century was determined not only by administrative and economic considerations but also by the political priorities of the republics' development, which is reflected in the documentary heritage preserved in the examined collections.
Conclusion. Archival sources serve as an important repository of historical information that broadens our understanding of the formation and development of the Kazakhstan — Russia border. They play a significant role in studying the process and stages of cross-border cooperation between the Republic of Kazakhstan and the Russian Federation. The presented archival materials will be valuable for researchers examining the history of relations between the two countries, for regional studies specialists focusing on border areas, and for international relations scholars analyzing the current state of Kazakhstan — Russia interactions. The use of newly introduced data makes it possible not only to clarify certain historical narratives but also to address topics that previously could not be analyzed due to the insufficiency of the empirical base.