the article continues the study of the biography, scientific and organizational-pedagogical activity of the protégé, comrade and friend of Academician V. I. Vernadsky – the prominent mineralogist, geochemist, professor Sergei Platonovich Popov (1872–1964), published in the previous issue of the journal. The period of his life in the 1930s, the war and post-war times are considered. The analysis of the correspondence of S. P. Popov with Academician V. I. Vernadsky allowed to identify the lines of intellectual tension «province –center» and to show the wide circle of communication of Professor S. P. Popov. Corpora of documents of the State Archives of the Russian Federation, the Archives of the Russian Academy of Sciences, the State Archives of the Republic of Crimea, the Institute of Archeography of the National Library of Ukraine named after V. I. Vernadsky are introduced into scientific circulation, which allowed to reveal unknown stories about the geologist’s work in Simferopol. The scientist’s attempts to leave Crimea due to the threat of dismissal to various academic centers are shown, which ended with Popov moving to Voronezh. The scientist’s activities are shown against the background of the socio-economic transformations taking place in the country and in its separate region.