The paper briefly outlines the history of Alma Mater Vilnensis from the university’s inception to the end of 1939, together with the research fields and organizational and teaching achievements of those Vilnius scholars who are mentioned relatively more frequently in the aforementioned correspondence. The author’s guiding idea was to show how considerably an additional source such as private correspondence can supplement official knowledge about individual scholars, their community and the times they live in. Extensively quoted excerpts from letters are sometimes supplemented by the author’s own observations and suggested literature of the subject. The text focuses mainly on the academic achievements and behaviours of SBU-affiliated researchers such as Jan Otrębski, Halina Turska, Jan and Halina Safarewicz, Olgierd Chomiński as well as others who appear in the background.