The service privileged class in tsarist Russia was heterogeneous both in composition and in ethnicity. An integral part of this class was such a category of service people as service Tatars. Under Peter I, the Russian service class underwent an evolution. The serving Tatars and Murza, who professed Islam, remained aloof from this process and were soon relegated to the category of taxable population. But already under Catherine II, justice was restored and many Tatar clans became noble.