In 1912, Friedrich Heinrich Lewy first described the inclusion bodies named after him and seen in paralysis agitans (p.a.). Tretiakoff had found (1919) that the nucleus niger is most likely to be affected but in a subsequent large-scale series of post-mortem examinations (1923). Lewy was able to confirm this for a minority of cases only, with the exception of those that displayed postencephalitic Parkinsonism (and an unknown number of atypical Parkinson syndrome cases not identified until the 1960s). In a speculative paper (1932), he saw similarities between inclusion bodies in p.a. and viral diseases like lyssa and postulated a viral genesis of p.a. In a historical review of basal ganglia diseases (1942), he did not mention the putative significance of the inclusion bodies for the post-mortem diagnosis. It seems that their importance was seen only after Lewy's death, long after Tretiakoff's initial naming of the 'corps de Lewy'. Lewy, however, had already described their diffuse and cortical distribution (1923). An identification of diffuse Lewy body disease or dementia followed much later. Lewy's career in many diverse branches of neurology and internal medicine was strongly affected by World War I and the difficult situation faced by Jews in Germany. Shortly after the Neurological Institute was founded in Berlin in 1932 (as a clinic and research institute), he was forced, in 1933, to emigrate. His exile in England and the United States mirrors the fate of many German Jews and academics in the first half of the 20th century.