June 20. June 20 is the 171st day of the year (172nd in leap years) in the Gregorian calendar; 194 days remain until the end of the year. Events Pre-1600 451 ??? Battle of Chalons: Flavius Aetius battles Attila the Hun. After the battle, which was inconclusive, Attila retreats, causing the Romans to interpret it as a victory. 1180 ??? First Battle of Uji, starting the Genpei War in Japan. 1295 ??? The Treaty of Anagni, an attempt mediated by the papacy to end the War of the Sicilian Vespers, is signed by the crown of Aragon, the kingdom of France and kingdom of Naples. 1601???1900 1622 ??? The Battle of H??chst takes place during the Thirty Years' War. 1631 ??? The Sack of Baltimore: The Irish village of Baltimore is attacked by Barbary slave traders. 1652 ??? Tarhoncu Ahmed...