1291: After 100 years of Crusader control, the last Crusader stronghold of Acre is reconquered and destroyed by the Mamluks under Sultan al-Ashraf Khalil

1804: Napoléon Bonaparte is proclaimed Emperor of France by the French Senate

1974: India becomes the sixth nation to explode an atomic bomb

1980: Eruption of Mount St. Helens in Washington state triggers the largest landslide in history, killing 57 people and causing over $1 billion in damage

2009: The Liberation Tigers of Tamil Eelam are defeated by the Sri Lankan government, ending the Sri Lankan Civil War and almost 26 years of fighting between the two sides

Source: Onthisday.com