In 1973 he was appointed Rouse Ball Professor of Mathematics at the University of Oxford and he continued to hold this until he became Emeritus Rouse Ball Professor of Mathematics in 1998.
Sa 1973 siya ay hihirangin pakilusin Ball Propesor ng Matematika sa Unibersidad ng Oxford at siya ang patuloy na humawak na ito hanggang siya ay naging Emeritus pakilusin Ball Propesor ng Matematika sa 1998.