Havelock Ellis

English physician

Henry Havelock Ellis, known as Havelock Ellis (2 February 1859 – 8 July 1939), was an English physician, eugenicist, writer, progressive intellectual and social reformer who studied human sexuality. He co-wrote the first medical textbook in English on homosexuality in 1897, and also published works on a variety of sexual practices and inclinations, as well as on transgender psychology.