The article analyzes the scientific activity of the forgotten Russian financier Vladimir Robertovich Idelson (1881-1954), who taught until 1918 at the St. Petersburg Polytechnic Institute. It was at the Polytechnic Institute that the courses on analyzing financial markets and banking were taught for the first time at a higher school. He analyzes his contribution to the establishment of training courses in tanks, the stock exchange and the money market in pre-revolutionary Russia. It shows its role in the development of certain types of insurance law in Russia, as well as the response to relevant financial projects being developed in pre-revolutionary Russia to improve banking, warehouses, and various types of insurance. The article highlights the activities of V. R. Idelson after emigrating to the UK, where he made a successful career as a lawyer, who participated in various financial disputes. Thanks to his brilliant knowledge and erudition, he gained respect and recognition in this country.