Wikipedia:Selected anniversaries/September 12
September 12: National Day in Cape Verde
- 1683 - Several European armies joined forces to defeat the Ottoman Empire at the Battle of Vienna
- 1933 - Leó Szilárd, waiting for a red light on Southampton Row in Bloomsbury, conceived of the idea of the nuclear chain reaction
- 1942 - The Laconia incident: RMS Laconia, carrying some 80 civilians and 268 British soldiers, and about 1800 Italian POWs with 160 Polish soldiers on guard, was hit by a torpedo from a U-boat off the coast of West Africa and sank.
- 1977 - South African anti-apartheid activist Steve Biko was killed in police custody.
- 1990 - The Two Plus Four Agreement was signed, paving the way for German re-unification.
Recent days: September 11 – September 10 – September 9