The article aims to clarify the formation of Professor Serhii Kopylov's personality as a talented scientist, his multifaceted scientific work, and its significance in Ukrainian historiography in the study of the problems of historiography, source studies, biography, philocarty, and local history. The methodological basis of the study consists of the principles of objectivity, historicism, systematicity, and comprehensiveness, as well as the ideas of the schools of Annals, New Social History, and the genius of A.D. Toynbee. The research methods used include the following: comparative-historical analysis, logical analysis, prospective analysis, chronological analysis, narrative analysis, scientific source criticism, periodization, and actualization. The scientific novelty lies in the attempt, made for the first time in historiography, to analyze the main areas of the scientist's research and, on this basis, to reconstruct a comprehensive picture of his scientific work and to determine its scientific value. Conclusions. The analysis of Serhii Kopylov's work has given grounds to distinguish the following four stages: Stage 1 (1963-1985) - the genesis of the personality traits of an intellectual from childhood to the end of his studies at the Faculty of History of Taras Shevchenko National University of Kyiv and his first steps in the field of historical research. His thesis became his first notable success in student research: it won first place in competitions of student research papers in the fields of history and later humanities, for which he was awarded a gold medal in 1986 by the Presidium of the Academy of Sciences of the Ukrainian SSR; the formation of professional skills characterized the 2nd period (1985-1997). This period was characterized by the formation of professional competencies of a historian-scientist (completion of postgraduate studies, defense of the PhD thesis at the end of 1988) and refocusing scientific interests from the study of Bulgarian studies to the problems of Ukrainian Slavic studies. The 3rd period (1998-2006) was marked by an intensive process of developing the talent of a researcher-analyst and improving his professional qualities, thus transforming into a well-known Ukrainian scholar of Slavic studies, as evidenced by the publication of dozens of articles, the monograph "Problems of the History of Slavic Peoples in the Historical Thought of Ukraine" (2005), and the defense of his doctoral dissertation "Ukrainian Historical Slavic Studies of Modern Times: Origins and Stages of Development" (2006); the 4th period (2007-2023) was marked by the flourishing of scientific creativity, which was based on the study of biography, history, source and local history, and philology. Serhii Kopylov's scientific achievements include more than 330 publications, including five monographs and eleven manuals and textbooks. His study made it possible, firstly, to recreate the integrity of the picture of the jubilee's scientific work, which is an organic combination of various objects of research; secondly, to identify its main directions, in which the author was able to achieve the most significant results: Ukrainian historical Slavic studies of modern times, biography, historiography, source studies, local history, and philocarty; thirdly, to reveal the decisive role in the development of methodological foundations of scientific creativity of the irrevocable break with the postulates of Soviet/Russian methodology that took place in the second half of the 90s XX century - the first half of the zero years of the XXI century.