October 8314 – Constantine I defeats Roman Emperor Licinius, who loses his European territories. 451 – The first session of the Council of Chalcedon begins. 876 – Frankish forces led by Louis the Younger prevent a West Frankish invasion and defeat emperor Charles II ("the Bald"). 1075 – Dmitar Zvonimir is crowned King of Croatia. 1200 – Isabella of Angoulême is crowned Queen consort of England. 1322 – Mladen II Šubić of Bribir is deposed as the Croatian Ban after the Battle of Bliska.
July 21356 BC – The Temple of Artemis in Ephesus, one of the Seven Wonders of the World, is destroyed by arson. 230 – Pope Pontian succeeds Urban I as the eighteenth pope. After being exiled to Sardinia, he became the first pope to resign his office. 285 – Diocletian appoints Maximian as Caesar and co-ruler. 365 – The 365 Crete earthquake affected the Greek island of Crete with a maximum Mercalli intensity of XI (Extreme), causing a destructive tsunami that affects the coasts of Libya and Egypt, especially Alexandria.
December 4771 – Austrasian king Carloman I dies, leaving his brother Charlemagne as sole king of the Frankish Kingdom. 963 – The lay papal protonotary is elected pope and takes the name Leo VIII, being consecrated on 6 December after ordination. 1110 – An army led by Baldwin I of Jerusalem and Sigurd the Crusader of Norway captures Sidon at the end of the First Crusade. 1259 – Kings Louis IX of France and Henry III of England agree to the Treaty of Paris, in which Henry renounces his claims to French-controlled territory on continental Europe (including Normandy) in exchange for Louis withdrawing his support for English rebels.
September 25275 – For the last time, the Roman Senate chooses an emperor; they elect 75-year-old Marcus Claudius Tacitus. 762 – Led by Muhammad al-Nafs al-Zakiyya, the Hasanid branch of the Alids begins the Alid Revolt against the Abbasid Caliphate. 1066 – In the Battle of Stamford Bridge, Harald Hardrada, the invading King of Norway, is defeated by King Harold II of England. 1237 – England and Scotland sign the Treaty of York, establishing the location of their common border.
August 28475 – The Roman general Orestes forces western Roman Emperor Julius Nepos to flee his capital city, Ravenna. 489 – Theodoric, king of the Ostrogoths, defeats Odoacer at the Battle of Isonzo, forcing his way into Italy. 632 – Fatimah, daughter of the Islamic prophet Muhammad, dies, with her cause of death being a controversial topic among the Sunni Muslims and Shia Muslims. 663 – Silla–Tang armies crush the Baekje restoration attempt and force Yamato Japan to withdraw from Korea in the Battle of Baekgang.
August 1474 BC – A group of officials, led by the Western Han minister Huo Guang, present articles of impeachment against the new emperor, Liu He, to the imperial regent, Empress Dowager Shangguan. 29 BC – Octavian holds the second of three consecutive triumphs in Rome to celebrate the victory over the Dalmatian tribes. 1040 – King Duncan I is killed in battle against his first cousin and rival Macbeth. The latter succeeds him as King of Scotland.
January 1627 BC – Gaius Julius Caesar Octavianus is granted the title Augustus by the Roman Senate, marking the beginning of the Roman Empire. 378 – General Siyaj K'ak' conquers Tikal, enlarging the domain of King Spearthrower Owl of Teotihuacán. 550 – Gothic War: The Ostrogoths, under King Totila, conquer Rome after a long siege, by bribing the Isaurian garrison. 929 – Emir Abd-ar-Rahman III establishes the Caliphate of Córdoba. 1120 – Crusades: The Council of Nablus is held, establishing the earliest surviving written laws of the Crusader Kingdom of Jerusalem.
October 211096 – A Seljuk Turkish army successfully fights off the People's Crusade. 1097 – First Crusade: Crusaders led by Godfrey of Bouillon, Bohemund of Taranto, and Raymond IV, Count of Toulouse, begin the Siege of Antioch. 1392 – Japanese Emperor Go-Kameyama abdicates in favor of rival claimant Go-Komatsu. 1512 – Martin Luther joins the theological faculty of the University of Wittenberg. 1520 – João Álvares Fagundes discovers the islands of Saint Pierre and Miquelon, bestowing them their original name of "Islands of the 11,000 Virgins".
October 16456 – Ricimer defeats Avitus at Piacenza and becomes master of the Western Roman Empire. 690 – Empress Wu Zetian ascends to the throne of the Tang dynasty and proclaims herself ruler of the Chinese Empire. 912 – Abd ar-Rahman III becomes the eighth Emir of Córdoba. 955 – King Otto I defeats a Slavic revolt in what is now Mecklenburg-Vorpommern. 1311 – The Council of Vienne convenes for the first time. 1384 – Jadwiga is crowned King of Poland, although she is a woman. 1590 – Prince Gesualdo of Venosa murders his wife and her lover.
December 15533 – Vandalic War: Byzantine general Belisarius defeats the Vandals, commanded by King Gelimer, at the Battle of Tricamarum. 687 – Pope Sergius I is elected as a compromise between antipopes Paschal and Theodore. 1025 – Constantine VIII becomes sole emperor of the Byzantine Empire, 63 years after being crowned co-emperor. 1161 – Jin–Song wars: Military officers conspire against the emperor Wanyan Liang of the Jin dynasty after a military defeat at the Battle of Caishi, and assassinate the emperor at his camp.
