Before the Nazis rose to power, Berlin was the undisputed gay capital of the world. It was not just the wild nightlife of gay bars, sex shows, transvestite shows, and prostitutes. Serious doctors were performing sex change operations and exploring the use of hormones. Publishers were printing thousands of books and magazines. In the 1930s, the Nazis arrested and murdered tens of thousands and destroyed the businesses and scientific institutes. Much of this history remained unknown because of the ongoing criminalization of homosexuality. It was not until the 1970s and the gay rights movement gained power that this history became rediscovered.