Physicist and atom spy, born in Rüsselsheim, WC Germany. He studied at Kiel and Leipzig, and escaped from Nazi persecution to Britain in 1933. Interned on the outbreak of World War 2, he was released and naturalized in 1942. From 1943 he worked in the USA on the atom bomb, and in 1946 became head of the theoretical physics division at Harwell, UK. In 1950 he was sentenced to 14 years' imprisonment for disclosing nuclear secrets to the Russians. On his release in 1959 he worked at East Germany's Central Institute for Nuclear Research until his retirement in 1979. He remained a committed communist, and received many honours from the East German Communist Party.