 He graduated a doctor of law from the German University in Prague (Deutsche Universität in Prag, Juridische Fakultät) on 11 February 1935, at the age of 23.In 1939 he emigrated to the United Kingdom, where he began his professional career as a Germanist, being active at Cambridge and London (England) and at Swansea (Wales).Heller became a British subject in 1947.