It is with deep regret that I announce that Donald Coxeter passed away on the evening of March 31, 2003.

Donald joined the Department of Mathematics at the University of Toronto in 1936 and he spent the next 67 years actively engaged at the University. He was the soul and spirit and the most active member of the geometry seminar.

Donald had been described by many as the greatest living geometer. Undoubtedly the world's best known geometer, Professor Coxeter has made contributions of fundamental importance to the Theory of Polytopes, Non-Euclidean geometry, Discrete Groups, and Combinatorial Theory. He is best known for his introduction of what are now referred to as Coxeter groups. His name is attached to a number of mathematical concepts including the Coxeter diagram, Coxeter complex, Coxeter element, Coxeter graph, Coxeter number, and Coxeter system.

Donald was a most prolific writer. He had over 200 publications including several books. His work was influential not only in geometry but also in many other branches of mathematics. Donald cherished the connection to music and arts. He was intimately involved in Escher's work.

Donald was widely recognized and honoured. He was a Fellow of the Royal Society of Canada (1947), Fellow of the Royal Society, London (1950), and Companion of the Order of Canada (1997). He holds a number of honorary degrees.

Donald remained active to the end. In July 2002 he gave an invited address at the conference in honour of Janos Bolyai on Hyperbolic Geometry in Budapest, Hungary, and he had just completed the final touches on his last paper.

He was 96 when he passed away. Donald is survived by his daughter Susan Thomas and his son Edgar.

John Bland
Chair
Department of Mathematics

Last updated: April 1, 2003