This paper discusses the contribution of two outstanding petroleum geologists, Academicians I.M. Gubkin and A.A. Trofimuk, to the development of the oil and gas complex of the Soviet Union and Russia. It presents a brief description of their biographies and the main results of their scientific, pedagogical, production, and organizational activities. The paper is a detailed preface to the special issue of the Russian Geology and Geophysics Journal dedicated to the 150th birth anniversary of I.M. Gubkin and the 110th birth anniversary of A.A. Trofimuk. A brief description of the papers published in the special issue is given.