Abstract. The article is devoted to scientific work of the eminent Don historian A.I. Agafonov. In article the main milestones of his work are provided, as well as key publications and general characteristics of his scientific achievements, selected important features of his works and methodological approaches. The focus is on the contribution of the scientist to the development of the Don history, the Don Cossack history, source studies, historiography, and special historical disciplines. In the article the attention is paid to his international projects and social achievements. It shows the level of his scientific and public recognition. A.I. Agafonov, linking his life with the university, is the author of several important monographs on the history of Cossacks and Don Region in the prerevolutionary period. As a student of A.P. Pronstein he made a significant contribution to the development of regional historiography, source studies, and special historical disciplines, introduced into scientific circulation a large number of new sources. A.I. Agafonov is actively involved in popularization of regional history, international projects, received several awards for his scientific and public work.
Keywords: A.I. Agafonov, historiography, source studies, history of the Don Region, Cossack history.