Portal:Conservatism/Selected anniversary/May
- 1979 – Margaret Thatcher becomes the first female Prime Minister of the United Kingdom.
- 1940 – the Norway Debate in the British House of Commons begins, and leads to the replacement of Prime Minister Neville Chamberlain with Winston Churchill three days later.
- 1988 – Section 28 is enacted in Great Britain with the effect of prohibiting the promotion of homosexuality by local authorities.