Abstract: The study describes the life and activities of outstanding Russian geologists of the late 19th to early 20th centuries, Karl I. Bogdanovich (1864-1947) and Gennadii D. Romanovsky (1830-1906). They shared a common background as they both were alumni and later full professors at the Mining Institute and their professional activity was inextricably linked to the first decades of the oil industry in Russia. The study pays much attention to how they developed their professional skills to become respected authorities in geological science as well as demanding and competent teachers at the Mining Institute. It stresses that they commanded great respect. For example, between 1914-1917, Bogdanovich led the Geological Committee of Russia (Geolkom), in 1918, he was elected first Dean of the Faculty of Geological Prospecting at the Mining Institute and did much to develop geology in Poland.