1866-1962

Vallée Poussin was born in 1866 in Louvain, Belgium. His father (professor of geology at the University of Louvain) encouraged him to become a teaching Jesuit, but found he was not suited for the seminary. He became interested in engineering and although he graduated in that venue, he soon devoted his academic life to pure mathematics. His position as assistant at the University of Louvain allowed him to work with Louis Claude Gilbert (one of his former teachers) and when Gilbert died unexpectedly at the age of 26, Vallée Poussin was promoted to Gilbert's chair in 1893. Although one of Vallée Poussin's papers on differential equations was a prize winner, he was best known for proving the prime number theorem. He also worked on algebraic and trigonometric polynomials. Vallée Poussin chaired the mathematics department at the University of Louvain for 50 years before he died in 1962.