Son of Herman Feshbach. He went on to graduate school at Stanford, obtaining his Ph.D. in 1976 under Greg Brumfiel. His thesis contained a brilliant generalization of the classical double coset formula-from homological algebra-to the framework of Lie groups. Mark then went on to Northwestern University where he taught for two years before joining our department in 1978 as an assistant professor. He was promo- ted first to associate professor and then to full professor in 1988. In his research Mark seemed to have a knack for homing in on results which were fundamental and of las- ting significance. In a number of instances lines of development which Mark started have subsequently been taken up and pursued further by others, but he was there first. His thesis work on the Becker-Gottlieb transfer for compact Lie groups is an example of this. So also is his work with Dave Benson on stable splittings of classifying spaces. It is definitive, and paved the way for others who have done further calculations and taken the theory further. Another example is Mark's construction of a transfer map for Hopf algebras in quite general circumstances. He was one of the world expertson group cohomology, making definitive calculations at various stages of his career: for orthogonal groups early on, and more recently for the symmetric groups. Although the cohomology of symmetric groups has been described many times, it is Mark's ap- proach which recently has inspired others to go further.