The book represents the first attempt to systematize biographical and bibliographic information about the bishops of the largest Old Believer branch – the Russian Orthodox Old Believer Church – during the Soviet period (1918-1991). The author seeks to trace its history through the destinies of individual people. The dictionary offered to the reader has no analogues. The publication is illustrated with rare archival documents and photographs. The book is addressed to students, graduate students, scientists and all those interested in Russian Orthodox history and culture.