Croatian probabilist who spent most of his career in the USA. Feller was author of the influential two-volume An Introduction to Probability Theory and its Applications. Volume 1 (1950) remained the standard introductory text for stochastic processes for several decades. He obtained his MSc at U Zagreb in 1925, and his PhD at U Göttingen in 1926 (aged 20). Following posts at U Kiel, U Copenhagen, U Stockholm, and U Lund, Feller emigrated to the USA where he held successive posts at Brown U (1939), Cornell U (1945), and Princeton U (1950). He was President of the IMS in 1947 and its Rietz Lecturer in 1955. Feller was elected to membership of the NAS in 1960. In 1970 he was posthumously awarded the National Medal of Science. An asteroid is named after him.

http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/feller-william.pdf Fuller biography, bibliography, and photograph.