In the UK, all homosexual acts between men were made a crime in 1885, with a maximum sentence of life imprisonment.
However, homosexual acts between males aged 21 or over were decriminalised in England and Wales in 1967. The age of consent was reduced to 18 in 1994 and then 16 in 2000
Homosexuality: reasons why the law changed
The Wolfenden Report
After WW2, there was an increase in prosecutions of gay men and by 1954 over 1,000 were in prison.
Following several trials, the government set up a committee to consider reform of the law.
After gathering evidence from police, psychiatrists, religious leaders and gay men, the committees report published in 1957 recommended that homosexual acts in private between consenting adults over 21 to be legalised.
Homosexuality: reasons why the law changed
Campaigns
The Homosexual Law Reform Society, made up of leading public figures, successfully campaigned for the change in law that legalised gay sex in 1967. Further campaigns by Stonewell led eventually to equalising the age of consent at 16.
Homosexuality: reasons why the law changed
Poloticians
E.g. Roy Jenkins supported the campaign for change and as Home Secretary he introduced the necessary legislation in 1967.
Others since have have introduced further legislation such as the 2010 Equality Act which outlaws discrimination of grounds of sexual orientation.