Physicist. B.Sc., Chemistry, University of Budapest (1947); Ph.C. (left Hungary in 1948). Technical Officer in the Polymer Division of the Research Department ICI Dyestuffs Division (1948-1955). Research Assistant (1955-1963); Lecturer (1963-1965); Reader (1965-1969); Research Professor in Polymers (1969-1991), Department of Physics, University of Bristol. W.W. Clyde Visiting Professor at the University of Utah (1982-1983); Professor Associate in the Department of Materials Engineering at Brunel University (late 1990s). Keller was elected to the Fellowship of the Royal Society in 1972 (Rumford Medal 1994). Among the honours he received were the High Polymer Prize of the American Physical Society (1964), the Swinburne Medal of the Plastics and Rubber Institute (1975), and the Max Born Medal of the Institute of Physics and German Physical Society. In 1998 Keller was elected an 'External Member of the Hungarian Academy of Science.