The article presents reflections on the fate of the outstanding anthropologist and archaeologist, one of the founders of Irkutsk University and founder of Irkutsk archaeological and ethnographic school B. E. Petri. First we published documents from the personal files of B. E. Petri and his wife L. I. Petri that were found in the archive of V. V. Svinin and illustrate some events of their life in the period of 1920–1930. We considered five documents, including the dismissal order of B.E. Petri from Irkutsk University in 1932, after which until his arrest in 1937, he could not find a job. We discuss the formation Baikal science (Baykalovedenie) as an interdisciplinary scientific direction, B. E. Petri role and his friendship with V. C. Dorogostaisky.