The ethnographic study of tribal groups is of great importance for understanding the history of an entire people. Such studies allow for a deeper understanding of the origin, formation, and interaction of different ethnic communities. In this article, based on the published documents and archival materials in Russian and Mongolian, an attempt by the author is made to reconstruct the history of the settlement of the Soyan tribal group of Tuvans. There is also an attempt to examine the related territorial dispute with the Mongols, which lasted through the 1930s and 1940s. It is shown that from the 17th century, the Soyans roamed over the vast territory of the Sayan Range and at different times paid tribute to the Altyn Khans, Dzungars, and Russians. Afterwards, the Soyans appeared in the south-western part of Tuva. In the mid-18th century, the Dorbets were resettled from the Ili and Tarbagatai regions to the vicinity of Ulaangom, which led to the displacement of the Soyans to the foothills of Tannu-Ola. Subsequently, by complaining to the Uliasutai Jian-Jun about the lack of pastures, the Tuvans obtained permission to roam in the Khan-Khokhii Range; in addition, territorial disputes, which had deep historical roots have periodically arisen between the Mongols and Tuvans. During the Qing rule, decisions were made by higher authorities (Uliasutai Jian-jun, and the Chamber of Foreign Relations), hopefully taking into account the opinions of all parties. The Tuvan People’s Republic and the Mongolian People’s Republic handled the border issue through more organized treaties, including with the participation of the USSR. The author concludes that the border issue between the Mongols and Tuvans was initially handled within the framework of the vertical management system of the Qing, but due to the protracted nature of the conflict and the change in the political landscape, this issue was transformed through a new format of interstate relations.