Italian astronomer Giovanni Cassini discovered Iapetus, Saturn’s third-largest moon.
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The British singer Cliff Richard was knighted by Queen Elizabeth II.
Benjamin O. Davis Sr. became the first African American US Army brigadier general.
Taylor Swift's third studio album 'Speak Now' was released. It won Billboard's 2011 Album of the Year.
St Katharine Docks opened in Central London, England, and it was one of the largest ports for trade in London in the 19th Century.
The Battle of Agincourt between the English and the French took place.
