Before 1933, male homosexual acts were illegal in Germany under Paragraph 175 of the German Criminal Code. The law was not consistently enforced, however, and a thriving gay culture existed in major German cities. After the Nazi takeover in 1933, the first homosexual movement's infrastructure of clubs, organizations, and publications was shut down. After the Röhm purge in 1934, persecuting homosexuals became a priority of the Nazi police state. A 1935 revision of Paragraph 175 made it easier to bring criminal charges for homosexual acts, leading to a large increase in arrests and convictions. Persecution peaked in the years prior to World War II and was extended to areas annexed by Germany, including Austria, the Czech lands, and Alsace–Lorraine.
The Nazi regime considered the elimination of all manifestations of homosexuality in Germany one of its goals. Men were often arrested after denunciation, police raids, and through information uncovered during interrogations of other homosexuals. Those arrested were presumed guilty, and subjected to harsh interrogation and torture to elicit a confession. Between 1933 and 1945, an estimated 100,000 men were arrested as homosexuals; around 50,000 of these were sentenced by civilian courts, 6,400 to 7,000 by military courts , and an unknown number by special courts. Most of these men served time in regular prisons, and between 5,000 and 6,000 were imprisoned in concentration camps. The death rate of these prisoners has been estimated at 60 percent, a higher rate than those of other prisoner groups. A smaller number of men were sentenced to death or killed at Nazi euthanasia centres. Nazi Germany's persecution of homosexuals is considered to be the most severe episode in a long history of discrimination and violence targeting sexual minorities.
After the war, homosexuals were initially not counted as victims of Nazism because homosexuality continued to be illegal in Nazi Germany's successor states. Few victims came forward to discuss their experiences. The persecution came to wider public attention during the gay liberation movement of the 1970s, and the pink triangle was reappropriated as an LGBT symbol.