1099-City of Jerusalem is captured and plundered by Christian forces during the First Crusade
1381-John Ball, a leader in the Peasants' Revolt, is hanged, drawn and quartered in the presence of Richard II of England
1410-Battle of Grunwald (First Battle of Tannenburg, Battle of Žalgiris), one of Medieval Europe's largest battles during the Polish-Lithuanian Teutonic War. Polish King Władysław Jagiełło and Lithuanian Grand Duke Vytautas defeat
1799-The Rosetta Stone is found in the Egyptian village of Rosetta by French Captain Pierre-François Bouchard during Napoleon's Egyptian Campaign
1941-Howard Florey and Norman Heatley present freeze-dried mold cultures of penicillin
1955-Eighteen Nobel laureates sign the Mainau Declaration against nuclear weapons, later co-signed by 34 more laureates
1994-Hundreds of thousands of Hutus flee to Zaire in the Congo near the end of the Rwandan Genocide
2012-Korean pop singer Psy releases single "Gangnam Style," it becomes a worldwide hit, topping the charts in over 36 countries