March 1509 BC – Publius Valerius Publicola celebrates the first triumph of the Roman Republic after his victory over the deposed king Lucius Tarquinius Superbus at the Battle of Silva Arsia. 293 – Emperor Diocletian and Maximian appoint Constantius Chlorus and Galerius as Caesars. This is considered the beginning of the Tetrarchy, known as the Quattuor Principes Mundi ("Four Rulers of the World"). 350 – Vetranio proclaims himself Caesar after being encouraged to do so by Constantina, sister of Constantius II.
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.
August 17310 – Pope Eusebius dies, possibly from a hunger strike, shortly after being banished by the Emperor Maxentius to Sicily. 682 – Pope Leo II begins his pontificate. 986 – Byzantine–Bulgarian wars: Battle of the Gates of Trajan: The Bulgarians under the Comitopuli Samuel and Aron defeat the Byzantine forces at the Gate of Trajan, with Byzantine Emperor Basil II barely escaping. 1186 – Georgenberg Pact: Ottokar IV, Duke of Styria and Leopold V, Duke of Austria sign a heritage agreement in which Ottokar gives his duchy to Leopold and to his son Frederick under the stipulation that Austria and Styria would henceforth remain undivided.
October 73761 BC – The epoch reference date (start) of the modern Hebrew calendar. 1403 – Venetian–Genoese wars: The Genoese fleet under a French admiral is defeated by a Venetian fleet at the Battle of Modon. 1477 – Uppsala University is inaugurated after receiving its corporate rights from Pope Sixtus IV in February the same year. 1513 – War of the League of Cambrai: Spain defeats Venice. 1571 – The Battle of Lepanto is fought, and the Ottoman Navy suffers its first defeat. 1691 – The charter for the Province of Massachusetts Bay is issued.
September 4476 – Romulus Augustulus is deposed when Odoacer proclaims himself "King of Italy", thus ending the Western Roman Empire. 626 – Li Shimin, posthumously known as Emperor Taizong of Tang, assumes the throne over the Tang dynasty of China. 929 – Battle of Lenzen: Slavic forces (the Redarii and the Obotrites) are defeated by a Saxon army near the fortified stronghold of Lenzen in Brandenburg. 1260 – The Sienese Ghibellines, supported by the forces of Manfred, King of Sicily, defeat the Florentine Guelphs at Montaperti.
July 271054 – Siward, Earl of Northumbria, invades Scotland and defeats Macbeth, King of Scotland, somewhere north of the Firth of Forth. 1189 – Friedrich Barbarossa arrives at Niš, the capital of Serbian King Stefan Nemanja, during the Third Crusade. 1202 – Georgian–Seljuk wars: At the Battle of Basian the Kingdom of Georgia defeats the Sultanate of Rum. 1214 – Battle of Bouvines: Philip II of France decisively defeats Imperial, English and Flemish armies, effectively ending John of England's Angevin Empire.
February 25138 – Roman emperor Hadrian adopts Antoninus Pius as his son, effectively making him his successor. 628 – Khosrow II, the last great Shah of the Sasanian Empire (Iran), is overthrown by his son Kavadh II. 1336 – Four thousand defenders of Pilenai commit mass suicide rather than be taken captive by the Teutonic Knights. 1705 – George Frideric Handel's opera Nero premiered in Hamburg. 1836 – Samuel Colt is granted a United States patent for his revolver firearm.
March 5363 – Roman emperor Julian leaves Antioch with an army of 90,000 to attack the Sasanian Empire, in a campaign which would bring about his own death. 1046 – Nasir Khusraw begins the seven-year Middle Eastern journey which he will later describe in his book Safarnama. 1279 – The Livonian Order is defeated in the Battle of Aizkraukle by the Grand Duchy of Lithuania. 1496 – King Henry VII of England issues letters patent to John Cabot and his sons, authorising them to explore unknown lands.
December 28418 – A papal election begins, resulting in the election of Pope Boniface I. 457 – Majorian is acclaimed as Western Roman emperor. 484 – Alaric II succeeds his father Euric and becomes king of the Visigoths. He establishes his capital at Aire-sur-l'Adour (Southern Gaul). 893 – An earthquake destroys the city of Dvin, Armenia. 1065 – Edward the Confessor's Romanesque monastic church at Westminster Abbey is consecrated. 1308 – The reign of Emperor Hanazono of Japan begins.
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.
