Prof. Mumford had worked and taught at Brown and Harvard Universities during his whole career. His work has been in both pure and applied mathematics. In pure mathematics, he centered on moduli problems, the roadmaps of algebraic geometry which have found application in string theory. In applied mathematics his concern was mathematical techniques and statistical models for perception, especially vision, and its neurophysiological embodiment in the brain. Most recently, he has been engaged in differential geometry and in the History of Mathematics. He has spent many semesters teaching and working in other countries, esp. at the Tate Institute in Mumbai, Warwick University, the Institut des Hautes Etudes Scientifique and the Institut Henri Poincare in Paris and the Isaac Newton Institute in Cambridge. He believes strongly that mathematics today has become a world-wide enterprise whose non-negotiable needs are open communication and travel, sharing ideas across all borders.