The monograph is devoted to the study of the history of the regions of Southern Russia bordering the Steppe of the 13th - first half of the 15th centuries. The study highlights the issues of administrative-political, economic, economic and ethnocultural integration of the South Russian lands into the state system of the Mongol Empire and Ulus Jochi (Golden Horde). Based on the analysis of a wide range of written and archaeological sources, the author comes to the conclusion that the so-called "contact zones" that existed throughout the Gold-Horde era were formed in a number of regions of the South Russian forest-steppe.