Research objectives: To analyze the evolution of the status of the institution of serving tarkhans of the Western Cis-Urals during the period of this territory’s entry into the Moscow state (second half of the 16th–17th centuries). Research materials: The empirical basis of the study is unpublished documents of the 17th century from the “Ufa Prikaznaya Izba” collection of the Russian State Archive of Ancient Acts, act materials from the Kazan Khanate period introduced into scientific circulation, as well as the works of scientists who touched upon the problem of the functioning of the institution of serving tarkhans in the Turkic-Tatar states and the Moscow principality in their works. Results and scientific novelty: The data revealing the legal status of the serving tarkhans in the eastern uluses of the Kazan Khanate were studied and summarized, and the evolution of the position of representatives of this stratum of service people of the Moscow state on the territory of the Ufa district in the 17th century was shown. Based on the studied materials, it was concluded that the tarkhans were an integral part of the Tatar service class who had significant patrimonial estates in the border regions of the Kazan Khanate. After the Urals became part of the Muscovite kingdom, the Russian administration maintained the previous rights of the tarkhans, including in the area of land ownership. Significant changes in the status of the tarkhans were noted in the second half of the 17th century, when a group of “new” tarkhans began to form from among the yasak population (Bashkirs) who did not have tax immunity, which contributed to the rapprochement of the tarkhans with representatives of the Bashkir class.