The article is devoted to the scientific biography of the Soviet medievalist, Doctor of Historical Sciences, Professor Nahum Abramovich Bortnik (1911-1977). The author pays special attention to the period of the Great Patriotic War. Letters addressed to N. A. Bortnik are introduced into scientific circulation. The letter of the writer Isaac Sadykov, who worked a lot in Sverdlovsk during the Great Patriotic War, sheds light on the literary life of the city. Special attention is paid to the discussions, sometimes acute, emotional, devoid of academic chic, which flared up between M. Ja. Sjuzjumov and N. A. Bortnik. The article publishes the minutes of the meeting of the Department of General History of the Ural State University. The author comes to the conclusion that it is necessary to reconstruct the scientific biographies of Soviet historians. This work is important for the preservation of the scientific heritage of our country. The publication of sources, in this case, is the only antidote against the tenets of "cathedral historiography" and empty references "separated by commas" in the notes for the next anniversary date. The article is a continuation of the study of the biographies of historians who were part of M. Ja. Sjuzjumov's "inner circle" and represents an independent scientific problem. The complete opposite of M. Ja. Sjuzjumov was undoubtedly N. A. Bortnik (1911-1977). They were separated by many things. Thus, M. Ja. Sjuzjumov belonged to the last generation of pre-revolutionary historians. Naum Abramovich Bortnik was a representative of the first generation of Soviet scientists. Professor Sjuzjumov has been developing the theory of dialectical continuity all his life; Professor Bortnik followed the "romantic school", highly appreciating the role of the masses of the people. M. Ja. Sjuzjumov saw echoes of political struggle in heretical movements; N. A. Bortnik insisted on the most important role of the leaders of the masses.