The name of Boris Lvovich Gershun (1870-1954) a well-known lawyer and public figure in pre-revolutionary Russia, in the 1920s early 1950s. The authoritative lawyer and organizer of the Russian lawyers association in Berlin and Paris is practically unknown to historians and law historians. This article introduces for the first time a number of sources from Collection No. 2316 (“Association of Russian Lawyers in France”) of the Bakhmetyevsky Archive of the Columbia University Library in New York, which shed light on the life and work of a jury attorney in Berlin (1918-1933) and in Paris (1834-1954) periods. The main focus of work, in addition to the practice of law, B.L. Gershun considered rallying lawyer emigrants from Russia into separate corporations in order to preserve the best pre-revolutionary traditions of the bar. In Berlin B.L. Gershun was professionally demanded, moreover, he was one of the founders and chairman of the board of the Union of Russian Barristers in Germany (1921-1933), headed the first