Introduction. The article discusses one understudied — though essential — issue from the history of Don Kalmyk Cossacks. It focuses on the shaping and development of the Buddhist clergy among Don Kalmyks in relation to the then official religious agenda of the Don Host. The examined period covers the earliest conversion of Kalmyks to Cossackhood and onwards throughout the 1840s, the latter years having witnessed a largest reform of Buddhist institutions and clerical hierarchies. Goals. The paper attempts an insight into adaptation practices once exercised by Kalmyks as a group with specific cultural and religious backgrounds in polyethnic environments, special attention be paid to how the Buddhist clergy developed and were subsequently incorporated into administrative and social structures of Don Cossacks. Results. The official religious policy within the Don Host was largely tolerant and sought to secure freedom of faith, modernize spiritual services by way of optimizing networks of khuruls and their staff, encouraging some professional training of the latter, introducing clerics into administrative structures and services as a special privileged community. The religious policy of Don authorities among Kalmyk Cossacks was distinguished by that the former tended to actively use a tool of faith in the latter’s further acculturation, education, sedentarization, and conversion to stationary economic practices.