Vsevolod Ivanovich Romanovsky was a Russian, Soviet and Uzbek mathematician, founder of the Tashkent school of mathematics.
Academician V. I. Romanovsky
While studying at St. Petersburg University
Andrey Andreyevich Markov was a Russian mathematician best known for his work on stochastic processes. A primary subject of his research later became known as the Markov chain. He was also a strong, close to master-level chess player.
Markov in 1886
Markov
Markov's headstone