November 24380 – Theodosius I makes his adventus, or formal entry, into Constantinople. 1190 – Conrad of Montferrat becomes King of Jerusalem upon his marriage to Isabella I of Jerusalem. 1221 – Genghis Khan defeats the renegade Khwarazmian prince Jalal al-Din at the Battle of the Indus, completing the Mongol conquest of Central Asia. 1227 – Gąsawa massacre: At an assembly of Piast dukes at Gąsawa, Polish Prince Leszek the White, Duke Henry the Bearded and others are attacked by assassins while bathing.
October 5610 – Heraclius arrives at Constantinople, kills Byzantine Emperor Phocas, and becomes emperor. 816 – King Louis the Pious is crowned emperor of the Holy Roman Empire by the Pope. 869 – The Fourth Council of Constantinople is convened to depose patriarch Photios I. 1143 – With the signing of the Treaty of Zamora, King Alfonso VII of León and Castile recognises Portugal as a Kingdom. 1450 – Louis IX, Duke of Bavaria expels Jews from his jurisdiction. 1607 – Assassins attempt to kill Venetian statesman and scientist Paolo Sarpi.
January 1049 BC – Julius Caesar crosses the Rubicon, signalling the start of civil war. 9 – The Western Han dynasty ends when Wang Mang claims that the divine Mandate of Heaven called for the end of the dynasty and the beginning of his own, the Xin dynasty. 69 – Lucius Calpurnius Piso Licinianus is appointed by Galba as deputy Roman Emperor. 236 – Pope Fabian succeeds Anterus to become the twentieth pope of Rome. 1072 – Robert Guiscard conquers Palermo in Sicily for the Normans.
July 6371 BC – The Battle of Leuctra shatters Sparta's reputation of military invincibility. 640 – Battle of Heliopolis: The Muslim Arab army under 'Amr ibn al-'As defeat the Byzantine forces near Heliopolis (Egypt). 1253 – Mindaugas is crowned King of Lithuania. 1348 – Pope Clement VI issues a papal bull protecting the Jews accused of having caused the Black Death. 1411 – Ming China's Admiral Zheng He returns to Nanjing after the third treasure voyage and presents the Sinhalese king, captured during the Ming–Kotte War, to the Yongle Emperor.
December 21AD 69 – The Roman Senate declares Vespasian emperor of Rome, the last in the Year of the Four Emperors. 1124 – Pope Honorius II is consecrated, having been elected after the controversial dethroning of Pope Celestine II. 1140 – After a siege of several weeks, the city of Weinsberg and its castle surrender to Conrad III of Germany. 1237 – The city of Ryazan is sacked by the Mongol army of Batu Khan. 1361 – The Battle of Linuesa is fought in the context of the Spanish Reconquista between the forces of the Emirate of Granada and the combined army of the Kingdom of Castile and of Jaén resulting in a Castilian victory.
October 141066 – The Norman conquest of England begins with the Battle of Hastings. 1322 – Robert the Bruce of Scotland defeats King Edward II of England at the Battle of Old Byland, forcing Edward to accept Scotland's independence. 1586 – Mary, Queen of Scots, goes on trial for conspiracy against Queen Elizabeth I of England. 1656 – The General Court of the Massachusetts Bay Colony enacts the first punitive legislation against the Religious Society of Friends. 1758 – Seven Years' War: Frederick the Great suffers a rare defeat at the Battle of Hochkirch.
May 21293 – Roman Emperors Diocletian and Maximian appoint Galerius as Caesar to Diocletian, beginning the period of four rulers known as the Tetrarchy. 878 – Syracuse, Sicily, is captured by the Muslim Aghlabids after a nine-month siege. 879 – Pope John VIII gives blessings to Branimir of Croatia and to the Croatian people, considered to be international recognition of the Croatian state. 996 – Sixteen-year-old Otto III is crowned Holy Roman Emperor. 1349 – Dušan's Code, the constitution of the Serbian Empire, is enacted by Dušan the Mighty.
December 563 BC – Cicero gives the fourth and final of the Catiline Orations. 633 – Fourth Council of Toledo opens, presided over by Isidore of Seville. 1033 – The Jordan Rift Valley earthquake destroys multiple cities across the Levant, triggers a tsunami and kills many. 1082 – Ramon Berenguer II, Count of Barcelona is assassinated, most likely by his brother, Berenguer Ramon II. 1408 – Seeking to resubjugate Muscovy, Emir Edigu of the Golden Horde reaches Moscow, burning areas around the city but failing to take the city itself.
April 8217 – Roman emperor Caracalla is assassinated and is succeeded by his Praetorian Guard prefect, Marcus Opellius Macrinus. 876 – The Battle of Dayr al-'Aqul saves Baghdad from the Saffarids. 1139 – Roger II of Sicily is excommunicated by Innocent II for supporting Anacletus II as pope for seven years, even though Roger had already publicly recognized Innocent's claim to the papacy. 1232 – Mongol–Jin War: The Mongols begin their siege on Kaifeng, the capital of the Jin dynasty.
October 9768 – Carloman I and Charlemagne are crowned kings of the Franks. 1238 – James I of Aragon founds the Kingdom of Valencia. 1410 – The first known mention of the Prague astronomical clock. 1446 – The Hangul alphabet is published in Korea. 1594 – Troops of the Portuguese Empire are defeated on Sri Lanka, bringing an end to the Campaign of Danture. 1604 – Kepler's Supernova is the most recent supernova to be observed within the Milky Way. 1635 – Roger Williams is banished from the Massachusetts Bay Colony after religious and policy disagreements.
