King Charles I of England sends soldiers to arrest members of Parliament, commencing England's slide into civil war.

Lady Astor is elected as a Member of the Parliament of the United Kingdom. She is the first woman to sit in the House of Commons. (Countess Markiewicz, the first to be elected, refused to sit.)

The U.K. Parliament passes the Dangerous Drugs Act outlawing cannabis.

The British Parliament enacts the Statute of Westminster 1931, establishing legislative equality between the self-governing dominions of the Commonwealth of Australia, the Dominion of Canada, the Irish Free State, Dominion of Newfoundland, the Dominion of New Zealand, and the Union of South Africa.

The Parliament of the United Kingdom passes the Misuse of Drugs Act 1971 banning the medicinal use of cannabis.