Léopold Leau (1868-1943) was a French mathematician, primarily known for his ties to  international auxiliary languages.
Delegation for the Adoption of an International Auxiliary Language was founded on 7 January 1901 on Leau's initiative. He co-wrote with Prof.  Louis Couturat the monumental Histoire de la Langue Universelle (1903) and its supplement  Les Nouvelles Langues Internationales (1907). 
References [ edit ]
^ Audin, Michèle (2011), , Lecture Notes in Mathematics, Fatou, Julia, Montel: The great prize of mathematical sciences of 1918, and beyond, Translated from the 2009 French original by the author 2014, Springer, Heidelberg, p. 97, doi: 10.1007/978-3-642-17854-2, ISBN 978-3-642-17853-5, MR 2768955 .
^ , Union for the international language, archived from History of IDO the original on 2016-03-03 , retrieved 2014-07-15 .
^ Müller, F. Max (July 1904). "Review: . Histoire de la Langue Universelle by L. Couturat & L. Leau" The Monist. 14 (4): 604–607.
^ Koerner, E. F. K. (1974), "An Annotated Chronological Bibliography of Western Histories of Linguistic Thought, 1822-1972. Part I: 1822-1915", Historiographia Linguistica, 1 (1): 81–94, doi: 10.1075/hl.1.1.06koe .