1014 - Battle of Clontarf: Brian Boru defeats Viking invaders, but is killed in battle.
1229 - Ferdinand III of Castile conquers Cáceres.
1343 - St. George's Night Uprising.
1348 - The founding of the Order of the Garter by King Edward III is announced on St George's Day.
1521 - Battle of Villalar: King Charles I of Spain defeats the Comuneros.
1597 - William Shakespeare's The Merry Wives of Windsor is first performed, with Queen Elizabeth I in attendance.
1635 - The first public school in the United States, Boston Latin School, is founded in Boston, Massachusetts.
1660 - Treaty of Oliwa is established between Sweden and Poland.
1661 - King Charles II of England, Scotland and Ireland is crowned in Westminster Abbey.
1815 - The Second Serbian Uprising - a second phase of the national revolution of the Serbs against the Ottoman Empire, erupts shortly after the annexation of the country to the Ottoman Empire.
1867 - William Lincoln patents the zoetrope, a machine that shows animated pictures by mounting a strip of drawings in a wheel.
1920 - The national council in Turkey denounces the government of Sultan Mehmed VI and announces a temporary constitution.
1920 - The Grand National Assembly of Turkey is founded in Ankara.
1923 - Inauguration ceremonies take place of Gdynia as a temporary military port and fishers' shelter.
1932 - The 153-year old De Adriaan Windmill in Haarlem, the Netherlands burns down.
1935 - The Polish Constitution of 1935 is adopted.
1935 - The first official Children's day is celebrated in Turkey.
1940 - The Rhythm Night Club fire at a dance hall in Natchez, Mississippi, kills 198 people.
1941 - World War II: The Greek government and King George II evacuate Athens before the invading Wehrmacht.
1942 - World War II: Baedeker Blitz – German bombers hit Exeter, Bath and York in retaliation for the British raid on Lübeck.
1948 - 1948 Arab-Israeli War: Haifa, the major port of Israel, is captured from Arab forces.
1949 - Chinese Civil War: Establishment of the People's Liberation Army Navy.
1955 - The Canadian Labour Congress is formed by the merger of the Trades and Labour Congress of Canada and the Canadian Congress of Labour.
1961 - Algiers putsch by French generals.
1967 - A group of young radicals are expelled from the Nicaraguan Socialist Party. This group goes on to found the Socialist Workers Party.
1968 - Vietnam War: Student protesters at Columbia University in New York City take over administration buildings and shut down the university.
1979 - Fighting in London between the Anti-Nazi League and the Metropolitan Police's Special Patrol Group results in the death of protester Blair Peach.
1982 - The Conch Republic is established
1985 - Coca-Cola changes its formula and releases New Coke. The response is overwhelmingly negative, and the original formula is back on the market in less than 3 months.
1987 - 28 construction workers die when the L'Ambiance Plaza apartment building collapses while under construction in Bridgeport, Connecticut.
1988 - Pink Floyd's album The Dark Side of the Moon leaves the charts for the first time after spending a record of 741 consecutive weeks (over 14 years) on the Billboard 200.
1990 - Namibia becomes the 160th member of the United Nations and the 50th member of the Commonwealth of Nations.
1993 - Eritreans vote overwhelmingly for independence from Ethiopia in a United Nations-monitored referendum.
1997 - Omaria massacre in Algeria: 42 villagers are killed.
2003 - Beijing closes all schools for two weeks because of the SARS virus.
2009 - The gamma ray burst GRB 090423 it's observed for 10 seconds as the most distant object of any kind and also the oldest known object in the universe.
215 BC - A temple is built on the Capitoline Hill dedicated to Venus Erycina to commemorate the Roman defeat at Lake Trasimene.