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.
February 11327 – The teenaged Edward III is crowned King of England, but the country is ruled by his mother Queen Isabella and her lover Roger Mortimer. 1411 – The First Peace of Thorn is signed in Thorn (Toruń), Monastic State of the Teutonic Knights (Prussia). 1662 – The Chinese general Koxinga seizes the island of Taiwan after a nine-month siege. 1713 – The Kalabalik or Skirmish at Bender results from the Ottoman sultan's order that his unwelcome guest, King Charles XII of Sweden, be seized.
September 1896 – Domitian, who has been conducting a reign of terror for the past three years, is assassinated as a result of a plot by his wife Domitia and two Praetorian prefects. 96 – Nerva is proclaimed Roman emperor after Domitian is assassinated. 324 – Constantine the Great decisively defeats Licinius in the Battle of Chrysopolis, establishing Constantine's sole control over the Roman Empire. 1048 – Battle of Kapetron between a combined Byzantine-Georgian army and a Seljuq army.
April 1527 – Byzantine Emperor Justin I names his nephew Justinian I as co-ruler and successor to the throne. 1081 – Alexios I Komnenos overthrows the Byzantine emperor Nikephoros III Botaneiates, and, after his troops spend three days extensively looting Constantinople, is formally crowned on April 4. 1572 – In the Eighty Years' War, the Watergeuzen capture Brielle from the Seventeen Provinces, gaining the first foothold on land for what would become the Dutch Republic.
August 27410 – The sacking of Rome by the Visigoths ends after three days. 1172 – Henry the Young King and Margaret of France are crowned junior king and queen of England. 1232 – Shikken Hojo Yasutoki of the Kamakura shogunate promulgates the Goseibai Shikimoku, the first Japanese legal code governing the samurai class. 1557 – The Battle of St. Quentin results in Emmanuel Philibert becoming Duke of Savoy. 1593 – Pierre Barrière failed an attempt to assassinate Henry IV of France.
August 15636 – Arab–Byzantine wars: The Battle of Yarmouk between the Byzantine Empire and the Rashidun Caliphate begins. 717 – Arab–Byzantine wars: Maslama ibn Abd al-Malik begins the Second Arab Siege of Constantinople, which will last for nearly a year. 718 – Arab–Byzantine wars: Raising of the Second Arab Siege of Constantinople. 747 – Carloman, mayor of the palace of Austrasia, renounces his position as majordomo and retires to a monastery near Rome. His brother, Pepin the Short, becomes the sole ruler (de facto) of the Frankish Kingdom.
January 9681 – Twelfth Council of Toledo: King Erwig of the Visigoths initiates a council in which he implements diverse measures against the Jews in Spain. 1127 – Jin–Song Wars: Invading Jurchen soldiers from the Jin dynasty besiege and sack Bianjing (Kaifeng), the capital of the Song dynasty of China, and abduct Emperor Qinzong of Song and others, ending the Northern Song dynasty. 1349 – The Jewish population of Basel, believed by the residents to be the cause of the ongoing Black Death, is rounded up and incinerated.
April 201303 – The Sapienza University of Rome is instituted by a bull of Pope Boniface VIII. 1653 – Oliver Cromwell dissolves England's Rump Parliament. 1657 – English Admiral Robert Blake destroys a Spanish silver fleet, under heavy fire from the shore, at the Battle of Santa Cruz de Tenerife. 1657 – Freedom of religion is granted to the Jews of New Amsterdam (later New York City). 1752 – Start of Konbaung–Hanthawaddy War, a new phase in the Burmese Civil War (1740–57).
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.
January 301018 – Poland and the Holy Roman Empire conclude the Peace of Bautzen. 1287 – King Wareru founds the Hanthawaddy Kingdom, and proclaims independence from the Pagan Kingdom. 1607 – An estimated 200 square miles (51,800 ha) along the coasts of the Bristol Channel and Severn Estuary in England are destroyed by massive flooding, resulting in an estimated 2,000 deaths. 1648 – Eighty Years' War: The Treaty of Münster and Osnabrück is signed, ending the conflict between the Netherlands and Spain.
