April 14 is the 104th day of the year (105th in leap years) in the Gregorian calendar; 261 days remain until the end of the year.

• 43 BC – Legions loyal to the Roman Senate, commanded by Gaius Pansa, defeat the forces of Mark Antony in the Battle of Forum Gallorum.^[1]
• 69 – Vitellius, commanding Rhine-based armies, defeats Roman emperor Otho in the First Battle of Bedriacum to take power over Rome.^[2]
• 966 – Following his marriage to the Christian Doubravka of Bohemia, the pagan ruler of the Polans, Mieszko I, converts to Christianity, an event considered to be the founding of the Polish state.^[3]
• 972 – Otto II, Co-Emperor of the Holy Roman Empire, marries Byzantine princess Theophanu. She is crowned empress by Pope John XIII in Rome the same day.^[4]
• 1395 – Tokhtamysh–Timur war: At the Battle of the Terek River, Timur defeats the army of the Golden Horde, beginning the khanate’s permanent military decline.^[5]
• 1471 – In England, the Yorkists under Edward IV defeat the Lancastrians under the Earl of Warwick at the Battle of Barnet; the Earl is killed and Edward resumes the throne.^[6]
• 1561 – A celestial phenomenon is reported over Nuremberg, described as an aerial battle.^[7]

• 1639 – Thirty Years’ War: Forces of the Holy Roman Empire and Electorate of Saxony are defeated by the Swedes at the Battle of Chemnitz, ending the military effectiveness of the Saxon army for the rest of the war and allowing the Swedes to advance into Bohemia.^[8]
• 1775 – The Society for the Relief of Free Negroes Unlawfully Held in Bondage, the first abolition society in North America, is organized in Philadelphia by Benjamin Franklin and Benjamin Rush.^[9]
• 1793 – The French troops led by Léger-Félicité Sonthonax defeat the slaves settlers in the Siege of Port-au-Prince.^[10]
• 1816 – Bussa, a slave in British-ruled Barbados, leads a slave rebellion, for which he is remembered as the country’s first national hero.^[11]
• 1849 – Hungary declares itself independent of Austria with Lajos Kossuth as its leader.^[12]
• 1858 – The 1858 Christiania fire severely destroys several city blocks near Stortorvet in Christiania, Norway, and about 1,000 people lose their homes.^[13]
• 1865 – U.S. President Abraham Lincoln is shot in Ford’s Theatre by John Wilkes Booth; Lincoln dies the following day.^[14]
• 1865 – William H. Seward, the U.S. Secretary of State, and his family are attacked at home by Lewis Powell.^[15]
• 1881 – The Four Dead in Five Seconds Gunfight occurs in El Paso, Texas.^[16]
• 1890 – The Pan-American Union is founded by the First International Conference of American States in Washington, D.C.^[17]
• 1894 – The first ever commercial motion picture house opens in New York City, United States. It uses ten Kinetoscopes, devices for peep-show viewing of films.^[18]
• 1895 – The 1895 Ljubljana earthquake, both the most and last destructive earthquake in the area, occurs.^[19]
• 1900 – The world’s fair Exposition Universelle opens in Paris.^[20]