Don Cossacks refers to cossacks that settled along the Don River, Russia it its lower and middle parts. This population was formed in the second half od the 16th century from runaway peasants. By the end of the century they were granted certain privileges in exchange to frontier military service as Don Cossack Voisko. Since 1786 the territory was officially called Don Voisko Lands, renamed into Don Voisko Province (Область Войска Донского) in 1870.