Abstract. During the first half of the XVIII century, the authorities of the Russian Empire carried out a number of reforms in relation to the Cossack Host. Basically, they were aimed at creating a closed social group of Cossacks, capable of incrementing by natural means, whose members would carry the border service. The Empress Catherine II not only consistently continued the policy of her predecessors in that direction, but also made an attempt to codify the Cossacks status within the framework of the 1767–1769 Legislative Commission. Different understandings of the Cossack status did not allow consensus to be reached. This caused rebellions in the Cossack regions of Zaporozhye, Don and Yaik in 1768–1774. During the next Russian-Turkish war, the government suppressed them and took control of the outskirts of the Empire. As a result, the Zaporozhian Host was eliminated (1775), the Yaik Host was pacified (1772, 1774), and the Don Host was placed under such strong control (1775) that it served as a template for reforming all other Cossack Hosts.
Keywords: Cossack Host, XVIII century, Catherine II, reforms, Legislative Commission, Don Host, Zaporozhian Host, Yaik Host.