[The first successful sex reassignment surgery: Magnus, Dora and the Institute of Sexology, Berlin in 1931].

Magnus Hirschfeld was a brilliant German doctor campaigning for the decriminalization and destigmatization of homosexuality. During the very liberal Weimar Republic (1918-1933) he published his avant-garde articles, he created his Institute of Sexual Sciences (Institut für Sexualwissenschaft), where the first published transgender surgery took place, performed on Dora Richter in 1931 (we will be interested in this first report of successful intervention) and multiplied the interventions to abolish paragraph 175, penalizing "sodomy". Ultimately the rise of Nazism forced him to flee his country and end his life in France. Hirschfeld's work remained unfinished. His political activism and his over-media coverage earned him numerous criticisms even within the gay and lesbian movement of the time. Who was this strange doctor (the Einstein of sex, as an American promoter presented him during his conferences in 1930) who combined the faults, for the time, of being at the same time Jewish, homosexual and leftist?