William Feller (1906 - 1970) American mathematician who specialized in probability theory, best known for the Feller process, and his classic textbook “An Introduction to Probability Theory and Its Applications”, Volume 1.

Feller was born in Zagreb (now the capital of Croatia) and christened after Saint Willibrord. He moved to Germany to study at Göttingen University, where he received his doctoral degree. Because of Nazism, he fled to Denmark, later Sweden and finally America, becoming a citizen just prior to World War II. As a member of the American Mathematical Society, Feller began the publication of the journal Mathematical Reviews.