William Threlfall  William Richard Maximilian Hugo Threlfall (25 June 1888 Dresden – 4 April 1949 Oberwolfach) was a British-born German mathematician who worked on algebraic topology. He was a coauthor of the standard textbook Lehrbuch der Topologie. In 1933 he signed the "Vow of allegiance of the Professors of the German Universities and High-Schools to Adolf Hitler and the National Socialistic State".