WHAT HAPPENED ON 15. AUGUST
Want to find out what all happened on 15. August

Arab–Byzantine wars: The Battle of Yarmouk between Byzantine Empire and Rashidun Caliphate begins. (15. August 636)

Arab–Byzantine wars: Maslamah ibn Abd al-Malik begins the Second Arab Siege of Constantinople, which will last for nearly a year. (15. August 717)

Arab–Byzantine wars: Raising of the Second Arab Siege of Constantinople. (15. August 718)

The Battle of Roncevaux Pass, at which Roland is killed. (15. August 778)

The Saracens conquer and destroy Taranto. (15. August 927)

Holy Roman Emperor Otto II is defeated by the Saracens in the Battle of Capo Colonna, in Calabria (15. August 982)

Byzantine general Eustathios Daphnomeles blinds and captures Ibatzes of Bulgaria by a ruse, thereby ending Bulgarian resistance against Emperor Basil II's conquest of Bulgaria. (15. August 1018)

King Duncan I is killed in battle against his first cousin and rival Macbeth. The latter succeeds him as King of Scotland. (15. August 1040)

King Macbeth is killed at the Battle of Lumphanan by the forces of Máel Coluim mac Donnchada. (15. August 1057)

The Pavian-born Benedictine Lanfranc is appointed as the new Archbishop of Canterbury in England. (15. August 1070)

The cave city of Vardzia is consecrated by Queen Tamar of Georgia. (15. August 1185)

The Battle of the Puig takes place in the context of the Spanish Reconquista pitting the forces of the Taifa of Valencia against the Kingdom of Aragon. The battle resulted in an Aragonese victory. (15. August 1237)

The foundation stone of Cologne Cathedral, built to house the relics of the Three Wise Men, is laid. (Construction is eventually completed in 1880.) (15. August 1248)

Michael VIII Palaiologos is crowned Byzantine emperor in Constantinople. (15. August 1261)

Mongol invasion of Japan: The Mongolian fleet of Kublai Khan is destroyed by a "divine wind" for the second time in the Battle of Kōan. (15. August 1281)

The city of Rhodes surrenders to the forces of the Knights of St. John, completing their conquest of Rhodes. The knights establish their headquarters on the island and rename themselves the Knights of Rhodes. (15. August 1309)

Francesco Sforza, lord of Milan, conquers Lucca. (15. August 1430)

The Empire of Trebizond surrenders to the forces of Sultan Mehmed II. This is regarded by some historians as the real end of the Byzantine Empire. Emperor David is exiled and later murdered. (15. August 1461)

Pope Sixtus IV consecrates the Sistine Chapel. (15. August 1483)

Afonso de Albuquerque of Portugal conquers Malacca, the capital of the Malacca Sultanate. (15. August 1511)