I was born in Kingston, Ontario, Canada in 1946. In 1964 I began my undergraduate studies at M.I.T. I spent my junior year (1966-67) in Paris. I returned to M.I.T. and graduated in 1968. I went to Berkeley in fall 1968 and got my PhD in 1973 under the direction of James Simons. I went to the Institute for Advanced Study in Princeton for my first job 1973-74. I was an assistant professor at Yale 1974- 78. In 1978 I got a Sloan Fellowship. I got my first tenure job at the University of Toronto in fall 1979 and received a Coxeter-James Prize from the Canadian Math Society. I left Toronto in fall 1980 to be a full professor at UCLA. In 1989 I left UCLA for the University of Maryland where I have been ever since. In 1990 I gave an invited address at the International Congress for Mathematicians in Kyoto.