He qualified as a doctor of medicine in at the University of Vienna. In , Freud left Austria to escape Nazi persecution. He died in exile in the United Kingdom in In founding psychoanalysis , Freud developed therapeutic techniques such as the use of free association and discovered transference , establishing its central role in the analytic process. Freud's redefinition of sexuality to include its infantile forms led him to formulate the Oedipus complex as the central tenet of psychoanalytical theory.