Abstract: The subject of this research is the process of Circassia’s involvement into the sphere of the military-political influence of Ottoman Empire throughout the XVI century. The highest level of integration of the Circassian political space into the Ottoman Empire was achieved during the 1570’s. In the long Ottoman–Safavid War (1578-1591), Circassia appeared as a regional ally, by providing the Ottoman Empire with its territory, manpower and material resources. The author underlines that during this timeframe there was a noticeable political convergence between the Circassian principalities with the Ottoman Empire and Crimean Khanate. Such phenomenon was a result of the Russia-Circassia military-political alliance (1552-157), which in turn was caused by the Crimean Khan Sahib I Giray’s military campaigns (1539, 1545, and 1551). Among the main conclusions of this research are the following: 1) a rapid decrease in intensity and political significance of the connections between the principalities of the Western Circassia and Moscow after the year 1562, and Eastern Circassia in 1570; 2) the Ottoman–Safavid War of 1578-1591 became an important milestone in establishment of the Ottoman sovereignty over Circassia.