Havelock Ellis was a British physician, writer and social reformer. Ellis is famous in the medical world for having studied human sexuality. He also co-authored the very first medical textbook in English that approached the topic homosexuality in 1897. Ellis published works on various sexual practices and inclinations, such as transgender psychology.
He served as vice-president to the Eugenics Education Society and wrote vast articles and studies on the subject. In January 1931 He resigned from the Eugenics Society, due to their stance on sterilization.