The publication presents documents collected in the Historical Archive of the Omsk Region and the State Archive of the Orenburg Region, covering the life and activities of the Sultan of the Middle Zhuz Sultanmamet - the influential foreman of the Kypchak ulus, cousin of Abylai Khan. In addition, the collection contains significant information on the activities of other influential sultans and batyrs of the Middle Zhuz of the second half of the 18th century. Published documents cover the chronological period from 1752 to 1788.