April 12240 – Shapur I becomes co-emperor of the Sasanian Empire with his father Ardashir I. 467 – Anthemius is elevated to Emperor of the Western Roman Empire. 627 – King Edwin of Northumbria is converted to Christianity by Paulinus, bishop of York. 1012 – Duke Oldřich of Bohemia deposes and blinds his brother Jaromír, who flees to Poland. 1204 – The Crusaders of the Fourth Crusade breach the walls of Constantinople and enter the city, which they completely occupy the following day.
March 231400 – The Trần dynasty of Vietnam is deposed, after one hundred and seventy-five years of rule, by Hồ Quý Ly, a court official. 1540 – Waltham Abbey is surrendered to King Henry VIII of England; the last religious community to be closed during the Dissolution of the Monasteries. 1568 – The Peace of Longjumeau is signed, ending the second phase of the French Wars of Religion. 1775 – American Revolutionary War: Patrick Henry delivers his speech – "Give me liberty, or give me death!" – at St.
February 26747 BC – According to Ptolemy, the epoch (origin) of the Nabonassar Era began at noon on this date. Historians use this to establish the modern BC chronology for dating historic events. 364 – Valentinian I is proclaimed Roman emperor. 1266 – Battle of Benevento: An army led by Charles, Count of Anjou, defeats a combined German and Sicilian force led by Manfred, King of Sicily. Manfred is killed in the battle and Pope Clement IV invests Charles as king of Sicily and Naples.
July 169 – Tiberius Julius Alexander orders his Roman legions in Alexandria to swear allegiance to Vespasian as Emperor. 552 – Battle of Taginae: Byzantine forces under Narses defeat the Ostrogoths in Italy, and the Ostrogoth king, Totila, is mortally wounded. 1097 – Battle of Dorylaeum: Crusaders led by prince Bohemond of Taranto defeat a Seljuk army led by sultan Kilij Arslan I. 1431 – The Battle of La Higueruela takes place in Granada, leading to a modest advance of the Kingdom of Castile during the Reconquista.
February 121096 – Pope Urban II confirms the foundation of the abbey of La Roë under Robert of Arbrissel as a community of canons regular. 1404 – The Italian professor Galeazzo di Santa Sophie performed the first post-mortem autopsy for the purposes of teaching and demonstration at the Heiligen–Geist Spital in Vienna. 1429 – English forces under Sir John Fastolf defend a supply convoy carrying rations to the army besieging Orléans in the Battle of the Herrings.
June 281098 – Fighters of the First Crusade defeat Kerbogha of Mosul at the battle of Antioch. 1360 – Muhammed VI becomes the tenth Nasrid king of Granada after killing his brother-in-law Ismail II. 1461 – Edward, Earl of March, is crowned King Edward IV of England. 1495 – A French force heavily defeats a much larger Neapolitan and Spanish army at the battle of Seminara, leading to the creation of the Tercios by Gonzalo de Córdoba. 1519 – Charles V is elected Emperor of the Holy Roman Empire.
July 26657 – First Fitna: In the Battle of Siffin, troops led by Ali ibn Abu Talib clash with those led by Muawiyah I. 811 – Battle of Pliska: Byzantine Emperor Nikephoros I is killed and his heir Staurakios is seriously wounded. 920 – Rout of an alliance of Christian troops from Navarre and Léon against the Muslims at the Battle of Valdejunquera. 1309 – The Holy Roman Emperor Henry VII is recognized King of the Romans by Pope Clement V. 1509 – The Emperor Krishnadevaraya ascends to the throne, marking the beginning of the regeneration of the Vijayanagara Empire.
November 23534 BC – Thespis of Icaria becomes the first recorded actor to portray a character on stage. 1248 – Conquest of Seville by Christian troops under King Ferdinand III of Castile. 1499 – Pretender to the throne Perkin Warbeck is hanged for reportedly attempting to escape from the Tower of London. He had invaded England in 1497, claiming to be the lost son of King Edward IV of England. 1531 – The Second War of Kappel results in the dissolution of the Protestant alliance in Switzerland.
November 28587 – Treaty of Andelot: King Guntram of Burgundy recognizes Childebert II as his heir. 936 – Shi Jingtang is enthroned as the first emperor of the Later Jin by Emperor Taizong of Liao, following a revolt against Emperor Fei of Later Tang. 1443 – Skanderbeg and his forces liberate Kruja in central Albania and raise the Albanian flag. 1470 – Champa–Đại Việt War: Emperor Lê Thánh Tông of Đại Việt formally launches his attack against Champa.
April 21753 BC – Romulus founds Rome (traditional date). 43 BC – Battle of Mutina: Mark Antony is again defeated in battle by Aulus Hirtius, who is killed. Antony fails to capture Mutina and Decimus Brutus is murdered shortly after. 900 – The Laguna Copperplate Inscription (the earliest known written document found in what is now the Philippines): the Commander-in-Chief of the Kingdom of Tondo, as represented by the Honourable Jayadewa, Lord Minister of Pailah, pardons from all debt the Honourable Namwaran and his relations.
