[5] The institute pioneered research and treatment for various matters regarding gender and sexuality, including gay, transgender, and intersex topics.

[8][9][10] The Institute of Sex Research was founded by Magnus Hirschfeld and his collaborators Arthur Kronfeld, a once famous psychotherapist and later professor at the Charité, and Friedrich Wertheim, a dermatologist.

[14][15] The building, located in the Tiergarten district, was purchased by Hirschfeld from the government of the Free State of Prussia following World War I.

[18][19] As well as being a research library and housing a large archive, the institute also included medical, psychological, and ethnological divisions, and a marriage and sex counseling office.

[20] Other fixtures at the institute included a museum for sexual artifacts, medical exam rooms, and a lecture hall.

[24] In addition, the institute advocated sex education, contraception, the treatment of sexually transmitted diseases, and women's emancipation.

This included the Scientific-Humanitarian Committee, Helene Stöcker's Deutscher Bund für Mutterschutz und Sexualreform [de], and the World League for Sexual Reform (WLSR).

[20][11] Visitors included René Crevel, Christopher Isherwood, Harry Benjamin, Édouard Bourdet, Margaret Sanger, Francis Turville-Petre, André Gide and Jawaharlal Nehru.

[37] Upon visiting the institute, Dora Russell reflected that it was "where the results of researches into various sex problems and perversions could be seen in records and photographs.

[42] Following looser regulation on advertising contraceptive methods, the institute published an educational pamphlet on the matter in 1928 which ultimately reached a distribution of about 100,000 copies by 1932.

[44] Hirschfeld originally used the term "sexual intermediaries" in the late nineteenth century to refer mostly to homosexual men and lesbians.

[45] His concept of broad sexual intermediacy among humans has been traced to roughly similar ideas held by Charles Darwin and Galen of Pergamon.

[48][52] Various endocrinologic and surgical services were offered, including an early modern sex reassignment surgery in 1931.

[54] Hirschfeld originally advised against sexual reassignment surgeries, but came to support them as a means of preventing suicide among transsexual patients.

[53] Additionally, hair removal treatments using the institute's X-ray facility were developed, though this caused some side effects such as skin burns.

[53] Professor of history Robert M. Beachy stated that, "Although experimental and, ultimately, dangerous, these sex-reassignment procedures were developed largely in response to the ardent requests of patients.

"[55] Hirschfeld worked with Berlin's police department to curtail the arrest of cross-dressers and transgender people, through the creation of transvestite passes.

[11][58] Different from the Others, a film co-written by Hirschfeld that advocated greater tolerance for homosexuals, was screened at the institute in 1920 to audiences of statesmen.

[65] Photographs of intersex cases were among the collections at the institute – these were used as part of an effort to demonstrate sexual intermediacy to the average layperson.

[11][9] A caricature of him appeared on the front page of Der Stürmer in February 1929; the Nazi Party attacked his Jewish ancestry as well as his theories about sex, gender, and sexuality.

In March 1933 Kurt Hiller, a lawyer affiliated with the institute, was sent to a concentration camp, where he was tortured, though he later fled Germany and survived the war.

After breaking into the building, the students destroyed much of what was inside, and looted tens of thousands of items – including works by authors who had been blacklisted in Nazi Germany.

[71] Four days later, the institute's remaining library and archives were publicly hauled out and burned in the streets of the Opernplatz by members of SA alongside the students.

Also burned were books by Jewish writers, and pacifists such as Erich Maria Remarque that were removed from local public libraries, bookshops, and the Humboldt University.

A street cleaner salvaged and stored it the day after the burnings, and it was donated to the Berlin Academy of Arts after World War II.

[71] The destruction of the institute preceded a wider campaign against sexual reform and contraception, which were perceived as a threat to the German birth rate.

[70] While many fled into exile, the radical activist Adolf Brand made a stand in Germany for five months after the book burnings, but in November 1933 he had given up gay activism.

[76] On 28 June 1934, Hitler conducted a purge of gay men in the ranks of the SA wing of the Nazis, which involved murdering them in the Night of the Long Knives.

The West German legislature also retained the Nazi amendments to Paragraph 175, making it impossible for surviving gay men to claim restitution for the destroyed cultural center.

[81] Li Shiu Tong lived in Switzerland and the United States until 1956, but as far as is known, he did not attempt to continue Hirschfeld's work.