Tambov Governorate
Kozlovsky Uyezd originally existed in the Tambov area. In the course of the administrative reforms of Peter the Great in 1708 and 1719, it became part of Azov Governorate. New administrative divisions established the Tambov Viceroyalty in 1779 and from 1796 Tambov Governorate, with an area of 66.5 thousand km2 divided into 12 uyezds. With almost no change to its boundaries, the Governorate remained in existence until 1928.