To the Problem of Studying Kinship Relations of the Cossacks Historian I. D. Popko. A letter from Matrona Anfimovna Revnivykh to Her Uncle

The article examines some aspects of the relationship between historian, educator and General of the Cossack troops Ivan Diomidovich Popko and individual relatives. A lot is known about some of them to judge what they represented and meant in the life of a historian. There were those whose information is found only a few times in letters and memoirs. But there were also those about whom nothing was known until today. There is no information about them in either personal or official documents. It is possible to find out about their existence only by one or two rare letters. The only letter from Matrona Anfimovna Revnivykh, daughter of historian's brother, to her uncle, sent on April 13, 1886 from Tyumen, was found and attributed in the State Archive of the Stavropol Territory. It allowed us to bring back from oblivion a person close to I. D. Popko and draw some conclusions about the relationships in his family.