Max Euwe
Machgielis "Max" Euwe  (20 May 1901 in Amsterdam – 26 November 1981 in Amsterdam) was the 5th World Chess Champion, from 1935 to 1937. He was a Dutch chess grandmaster, mathematician, and author. He was not a full-time professional player; he got his PhD in pure mathematics in 1926, and worked as a school and college teacher. He was made Professor of Mathematics in 1964.p132