May 28585 BC – A solar eclipse occurs, as predicted by the Greek philosopher and scientist Thales, while Alyattes is battling Cyaxares in the Battle of the Eclipse, leading to a truce. This is one of the cardinal dates from which other dates can be calculated. 621 – Battle of Hulao: Li Shimin, the son of the Chinese emperor Gaozu, defeats the numerically superior forces of Dou Jiande near the Hulao Pass (Henan). This victory decides the outcome of the civil war that followed the Sui dynasty's collapse in favour of the Tang dynasty.
October 2829 – Theophilos succeeds his father Michael II as Byzantine Emperor. 939 – Battle of Andernach: Otto I, Holy Roman Emperor, crushes a rebellion against his rule, by a coalition of Eberhard of Franconia and other Frankish dukes. 1263 – The Battle of Largs is fought between Norwegians and Scots. 1470 – The Earl of Warwick's rebellion forces King Edward IV of England to flee to the Netherlands, restoring Henry VI to the throne. 1552 – Russo-Kazan Wars: Russian troops enter Kazan.
July 17180 – Twelve inhabitants of Scillium (near Kasserine, modern-day Tunisia) in North Africa are executed for being Christians. This is the earliest record of Christianity in that part of the world. 1048 – Damasus II is elected pope, and dies 23 days later. 1203 – The Fourth Crusade assaults Constantinople. The Byzantine emperor Alexios III Angelos flees from his capital into exile. 1402 – Zhu Di, better known by his era name as the Yongle Emperor, assumes the throne over the Ming dynasty of China.
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.
May 1028 BC – A sunspot is observed by Han dynasty astronomers during the reign of Emperor Cheng of Han, one of the earliest dated sunspot observations in China. 1291 – Scottish nobles recognize the authority of Edward I of England pending the selection of a king. 1294 – Temür, Khagan of the Mongols, is enthroned as Emperor of the Yuan dynasty. 1497 – Amerigo Vespucci allegedly leaves Cádiz for his first voyage to the New World. 1503 – Christopher Columbus visits the Cayman Islands and names them Las Tortugas after the numerous turtles there.
May 2617 – Germanicus celebrates a triumph in Rome for his victories over the Cherusci, Chatti, and other German tribes west of the Elbe. 451 – Battle of Avarayr between Armenian rebels and the Sasanian Empire takes place. The Sasanids defeat the Armenians militarily but guarantee them freedom to openly practice Christianity. 946 – King Edmund I of England is murdered by a thief whom he personally attacks while celebrating St Augustine's Mass Day. 961 – King Otto I elects his six-year-old son Otto II as heir apparent and co-ruler of the East Frankish Kingdom.
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.
February 8421 – Constantius III becomes co-Emperor of the Western Roman Empire. 1238 – The Mongols burn the Russian city of Vladimir. 1250 – Seventh Crusade: Crusaders engage Ayyubid forces in the Battle of Al Mansurah. 1347 – The Byzantine civil war of 1341–47 ends with a power-sharing agreement between John VI Kantakouzenos and John V Palaiologos. 1575 – Leiden University is founded, and given the motto Praesidium Libertatis. 1587 – Mary, Queen of Scots, is executed on suspicion of having been involved in the Babington Plot to murder her cousin, Queen Elizabeth I.
September 2338 – Drusilla, Caligula's sister who died in June, with whom the emperor is said to have an incestuous relationship, is deified. 1122 – Pope Callixtus II and Holy Roman Emperor Henry V agree to the Concordat of Worms to put an end to the Investiture Controversy. 1338 – The Battle of Arnemuiden, in which a French force defeats the English, is the first naval battle of the Hundred Years' War and the first naval battle in which gunpowder artillery is used.
1965January 1965 February 1965 January 14 – The Prime Minister of Northern Ireland and the Taoiseach of the Republic of Ireland meet for the first time in 43 years. January 20 Lyndon B. Johnson is sworn in for a full term as President of the United States. Indonesian President Sukarno announces the withdrawal of the Indonesian government from the United Nations. January 30 – The state funeral of Sir Winston Churchill takes place in London with the largest assembly of dignitaries in the world until the 2005 funeral of Pope John Paul II.
