Maurice Kraïtchik (1882-1957) and his contributions to recreational mathematics

Using archival sources, this article reconstructs little-known elements of the biography of Maurice Kraïtchik (1882-1957) and follows his activities from early work in Belgium to his exile in the United States. Particular attention is given to his role as editor of the Sphinx Revue and organizer of the Congrès International de Récréation Mathématique , which created new spaces for mathematical exchange. The article argues that Kraïtchik’s career illustrates the ambiguity between “amateur” and “professional” mathematics and shows how recreational problems, journals, and communities formed a significant part of twentieth-century mathematical culture.