Harold Scott MacDonald Coxeter

Harold Scott MacDonald Coxeter (1907 to 2003), known as Donald, was a geometer born in London who spent most of his career at the University of Toronto. He studied at Cambridge, where he took his doctorate in 1931 under H. F. Baker with a thesis on regular polytopes, and he was also influenced by Alicia Boole Stott and G. H. Hardy. His work centred on geometry, with major contributions to the theory of polytopes, non-euclidean geometry, group theory and combinatorics. In 1934 he classified the spherical and euclidean reflection groups that now carry his name, the Coxeter groups. Among his best known books are Regular Polytopes, Non-euclidean Geometry, Introduction to Geometry and, with S. L. Greitzer, Geometry Revisited. He was elected a Fellow of the Royal Society of Canada in 1948 and of the Royal Society of London in 1950.