Service class people
Service class people (Russian: служилые люди) were persons bound by obligations of service, especially military service, to the Muscovite Russian state.
In early Siberia, service-men and promyshleniks were the two main classes of the Russian population. Service-men were nominally servants of the tsar, had certain legal rights and duties and could expect pay if they were lucky. Promyshleniks were free men who made their living any way they could. A minor group were sworn-men (tseloval'niki, literally [cross or bible] 'kissers').
These men swore an oath and gained certain rights and duties. In practice the groups blended into each other, and the distinction was most important when dealing with the government. When petitioning the tsar, a service-man would call himself 'your slave' and a promishlenik 'your orphan'. These people were often called Cossacks, but only in the loose sense of being neither landowners nor peasants.