This essay is dedicated to the life and academic and teaching activities of Sergey Ivanovich Vavilov (1891–1951), an outstanding physicist, full member of the USSR Academy of Sciences, organizer of sci- entific teams and а prominent public figure. From 1945 until the end of his life, Vavilov was President of the USSR Academy of Sciences. He founded a large scientific school in the area of physical optics, ex- plored the phenomenon of luminescence and identified its practical significance. For the discovery and theoretical substantiation of the Vavilov–Cherenkov effect in 1958, the Russian scientists were awarded a Nobel prize. Vavilov’s studies laid the groundwork for the development of nonlinear physics. His scholarly works were awarded the State (Stalin) Prize four times. Vavilov’s research in the history of sci- ence is widely known. He also translated Newton’s ‘Opticks’ into Russian. The article also dwells on the tragic fate of his older brother, N.I. Vavilov (1887–1943), academician, biologist and genetic scientist.