The article analyzes main sources for genealogical study of service families of the 17th century. The subject of the study is sources on history and genealogy of service class families in the 17th century, revealed in specific study of O(A)stafievs, boyar scions of the Chernavsk uezd. The relevance of the study is determined by lack of scientific publications containing analysis of sources on the genealogy of service class people in Russia (and particularly, in “territory of the southern borderland”) of the time. It should be noted that genealogical aspects of formation of the military-service corporation of the Chernavsk uezd is virtually absent in scholarship. Relying on documentary, analytical, systemic, chronological, and biographical methods, the authors have examined unpublished archival sources from the fonds of the Order-in-charge (Razryadny) and Domestic (Pomestny) Prikazes from the Russian State Archive of Ancient Acts. These are desyatni (books on armament capability, allocation, distribution of allowance), annual budget books, krestoprivodnye knigi (pledge of allegiance books), pistsovye knigi (owner land descriptions), otkaznye knigi (land grants books), petitions, revisions of service class people, etc. Working with these historical sources has allowed the authors to carry out a comprehensive genealogical study and to systematize data on life, family ties, specifics of military service of the service class families representatives in the southern borderlands in the 17th century, in particular, O(A)stafievs, boyar scions of the Chernavsk uezd. As a result of the study, many documents have been introduced into scientific use. The historical and genealogical research carried out by the authors has now been brought up to the 1640s. It has been established that boyar scions Astafyevs were among the first settlers in the uezd who received estates for service from Tsar Alexei Mikhailovich Romanov in the mid-17th century. One of unresolved issues in the study is the question of the Astafievs' “exodus” to Chernavsk, in other words, identification of their former place of residence. Service class people moved to different uezds for various reasons (lack of land, the development of new territories, military conflicts, etc.) thus expanding their familial geography. This fact indicates that in the course of studying genealogy of service class families, certain problems may arise associated with absence or fragmentation of sources for individual uezds and difficulties in determining the family ties, especially in the early 17th century.
TO THE PROBLEM OF STUDYING THE PREREQUISITES OF THE NATIONAL STATEHOOD OF THE CHUVASH