Pink triangle in the context of Badge of shame

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, claiming it was a Jewish conspiracy to undermine the German people. 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 [de], 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.

Over the course of its history, the LGBTQ community has adopted certain symbols for self-identification to demonstrate unity, pride, shared values, and allegiance to one another. These symbols communicate ideas, concepts, and identity both within their communities and to mainstream culture. The two symbols most recognized internationally are the pink triangle and the rainbow flag.

The inverted black triangle (German: schwarzer Winkel) was an identification badge used in Nazi concentration camps to mark prisoners designated asozial  (de) ("a(nti-)social") and arbeitsscheu ("work-shy"). The Roma and Sinti people were considered asocial and tagged with the black triangle. The designation also included disabled individuals, alcoholics, beggars, homeless people, nomads, and prostitutes (though male sex workers were marked with the pink triangle), as well as violators of laws prohibiting sexual relations between Aryans and Jews. Queer women and transgender people from the female sex were also deemed to be anti-social, including lesbians and others deemed as nonconformists.