The phenomenon of so-called St. Petersburg historical school has long attracted the attention of researchers. The main sources of the formation of this scholastic discourse date back to the first decades of the XXth century (texts of P.N. Milyukov, A.E. Presnyakov, S.F. Platonov). It was on them that the subsequent historiographic tradition of the Soviet and post-Soviet period was based. Meanwhile, the researchers interpreted the concept of the «St. Petersburg Historical School» differently, singling out various factors of its formation. In this context, the work of S.N. Valk, A.N. Tsamutali, V.M. Paneyakh, B.V. Anan'ich, S.O. Schmidt, V.S. Brachev, a number of other researchers can be analized. It is noted in the article that in the last decade historians have distanced themselves from the dogmatic, categorical descriptions of the phenomenon of the «St. Petersburg school», paying more attention to the problems of the anthropology of science, the study of communications in the scientific community of the second half of the XIXth and early XXth centuries. In this article, the authors represent some results of a research project designed to take a new step in studying the problem of the St. Petersburg historical school. Basing on the extensive biographical database, the researchers attempted to consider the collective portrait of the school through the prism of prosopographical analysis. Its results not only made it possible to demonstrate clearly the distribution of the hull of St. Petersburg historians of the nineteenth and early twentieth centuries between various scientific departments and institutions, but also enabled the authors to put forward a number of well-reasoned hypotheses that overcome the usual historiographic cliches associated with the description of the St. Petersburg historical school of the pre-revolutionary period.