This article discusses the life and work of a talented Russian legal scholar and international lawyer, an authoritative public and political figure of the late 19th - first half of 20nd centuries, Professor of St. Petersburg University, Baron Mikhail Alexandrovich Taube, 150 years since his birth which was celebrated in 2019. M. A. Taube occupied a prominent place in the scientific, educational, social and political life of both pre-revolutionary and foreign emigrant Russia, was prolific in many fields of scientific knowledge and socially significant activity, but having left Russia after the October revolution of 1917, was forgotten for many years. The article is based on the domestic, foreign scientific materials, and archival sources, including the half-forgotten scientific works of M. A. Taube in the field of theory and history of international law, as well as archival material, mostly new and original, discovered by the authors in the state archives of St. Petersburg and the Bakhmeteff archive of Columbi