A Russian mathematician noted for major contributions in various scientific fields including classical mechanics, probability theory, and fluid mechanics. He studied at the Moscow State University and the Chemistry Technological Institute, graduating in 1929. He became a professor at Moscow University two years later, and went on to become the world’s foremost expert in probability theory. In 1935 he became the first chairman of probability theory at the Moscow State University. He was elected to the USSR Academy of Sciences in 1939. He held a number of positions at Moscow State University including head of several departments and served as the dean of the faculty of mechanics and mathematics.