Wikipedia:Selected anniversaries/June 20
On June 20:
- 1756 - A British garrison was imprisoned in the Black Hole of Calcutta.
- 1789 - 577 Deputies of the French Third Estate (commoners) took the Tennis Court Oath, starting the French Revolution.
- 1837 - Queen Victoria succeeded to the British throne.
- 1947 - A Mafia hitman murdered gangster Bugsy Siegel in Las Vegas, Nevada.