The eight stamps celebrate a march that took place from Trafalgar Square to Hyde Park in London in July 1972, which was the first to bear the name Gay Pride Rally.
The march was inspired by events in the United States, where the first Pride events had taken place to commemorate the anniversary of the Stonewall riots in New York.
The stamps, specially commissioned by Royal Mail, were illustrated by award-winning artist Sofie Birkin, art directed by NB Studio and Royal Mail consulted with its internal LGBT & Friends Network.
They depict the first Gay Pride rally and early Pride events where participants shouted slogans such as, “Gay is fun! Gay is proud! Gay is beautiful!”, to the more recent update on the traditional rainbow flag.
David Gold, of Royal Mail, said: “The vibrant, colourful Pride events that take place in towns and cities across the UK today trace their origins to a small number of people who marched through central London half a century ago to raise awareness of discrimination and inequality.
“There have been huge changes in laws and social attitudes, but Pride events continue to play a key role in raising awareness of discrimination, as well as celebrating diversity and individualism.”
Alan Dye, creative director of NB Studio, said: “It was a real honour to be asked to design this iconic series for the Royal Mail, as they represent such an important part of British LGBTQ+ history.
“Watching these beautiful illustrations come to life, you could easily imagine yourself as part of the ‘March Through Time’.”
NB Studio has created a film using the illustrations featured in the stamps, in collaboration with animation studio Animade.