Andrey Markov, Russian mathematician and theorist (b. 1856)
Andrey Andreyevich Markov (14 June 1856 – 20 July 1922) was a Russian mathematician best known for his work on stochastic processes. A primary subject of his research later became known as Markov chains or Markov processes.Markov and his younger brother Vladimir Andreevich Markov (1871–1897) proved the Markov brothers' inequality.
His son, another Andrey Andreyevich Markov (1903–1979), was also a notable mathematician, making contributions to constructive mathematics and recursive function theory.