In 1907, Berlin witnessed the publication of a curious book entitled Aus den Mädchenjahren eines Mannes (Of a Man’s Maiden Years), written under the pseudonym N. O. Body. The book was immensely popular: it quickly went through several editions and was even adapted twice to film, in 1912 and 1919.2 Despite the seemingly self-effacing pseudonym, it was well known that Of a Man’s Maiden Years were the memoirs of German-Jewish Karl Baer, born in 1885 with hypospadias, a comparatively common birth defect resulting in the displacement of the urethra on the penis.3 Because of his unusually shaped genitals, Baer was raised as a girl, Martha, despite the fact that he was hormonally and, in accordance with present-day knowledge, genetically male.4 At the age of twenty-one, Baer decided to change sex and live as a man after he had fallen in love with a married woman.5 He consulted a number of medical experts in the German capital and, like many other individuals who were classified as cases of ‘uncertain’ or ‘mistaken’ sex, was soon referred to the Institute for Sexual Research, led by eminent German sexologist Magnus Hirschfeld.6 Having been examined by several of Hirschfeld’s colleagues, including Iwan Bloch, Baer was diagnosed as a male pseudohermaphrodite, to draw on the terminology used at the time, and was allowed to change sex legally.