There was a stigma attached to homosexuality in decades past that made most gays suppress or hide their orientation. Legal prosecution of gays goes back at least to the 1533 Buggery Act, and likely before. By the middle of the 20th century the offenses were no longer punishable by hanging, and a number of high-profile arrests, including that of a WW II codebreaker (and later artificial intelligence pioneer) Alan Turin outraged the public, leading to further relaxing of sanctions. The social condemnation proved harder to overcome when the Gay Liberation Front, a gay civil rights organization, decided to organize a parade to encourage gay men and women to embrace their orientation.

On this day, July 1, in 1972 the first UK Gay Pride Rally took place in London, with 700 activists parading through bewildered crowds and a heavy police presence. Participants staged an act of civil disobedience when they kissed each other, an act forbidden by law at the time between men.

Today, Pride London continues to be an annual event, with over a million participants in 2010 making it the largest outdoor even in Britain that year. The day of the event is chosen to correspond to the Stonewall Riots in Greenwich Village, a spontaneous mass demonstration against the police raid on Stonewall Inn, a gay nightclub.