The article presents the first experiment in compiling a biography of the priest Anatoly Aleksandrovich Maslennikov, who was shot in Tomsk in 1920 on charges of belonging to the White Guard organization and canonized by the Russian Orthodox Church Abroad in 1981. During the study, a huge number of documentary sources stored in state and departmental archives of Sverdlovsk, Tyumen and Tomsk Oblasts, as well as church periodicals, reference and scientific literature, and also the personal archive of E. Simpson (Great Britain) have been examined. This study provides materials for compiling a socio-cultural portrait of an Orthodox clergy representative who became a participant of the Civil War: his social background, education, and marital status. Some new biographical details have been discovered and the known data clarified, including the periods of his ministry as the prior of Zavodo-Uspensky parish in Tyumen District of Tobolsk Province (now Tugulymsky District of Sverdlovsk Oblast), the regimental priest in the White Army, and the priest in the Baturinskoe village of Tomsk Province (now Tomsk District of Tomsk Oblast). The fact of Maslennikov's training at Kurgan Theological School is published for the first time; his study at Tobolsk Theological Seminary is also considered. The circle of the priest's relatives has been determined. After the successful graduation from Tobolsk Theological Academy in 1913, Maslennikov married, was ordained to the priesthood and appointed Prior of Church of the Assumption of the Mother of God in the village of Zavodo-Uspenskoye. Before the Civil War, he served in the parish, educating peasants in addition to the church service. Father Anatoly did not share revolutionary ideas, and with the outbreak of the Civil War in the Urals he transferred to the military department and was sent to the 16th Ishim Regiment under the command of Colonel N.N. Kazagrandi. With the retreating army of Admiral Kolchak, the priest and his family arrived to Tomsk, and here, after the defeat of the Whites, he was appointed priest of the Church of St. George the Victorious in the Baturinskoe village near Tomsk in December 1919. On May 14, 1920, he was arrested on charges of belonging to the White Guard organization, and, after a short-term investigation, priest Anatoly was shot on June 25, among many other victims of the fierce civil confrontation. In 1994 Anatoly Maslennikov was rehabilitated. The study of individual biographies within the context of the era allows expanding the possibilities of compiling prosopographies (dynamic collective biographies of social groups) and revealing the socio-cultural characteristics of the clergy of the Russian Orthodox Church during the period of the most powerful social transformation of society in the 20th century.