April 23 is the 113th day of the year in the Gregorian Calendar (114th in leap years). There are 252 days remaining.
- 215 BC - A temple is built on the Capitoline Hill dedicated to Venus Erycina to commemorate the Roman defeat at Lake Trasum.
- 303 - Saint George is put to death because of his strong faith in Christianity.
- 1014 - Battle of Clontarf: Brian Boru defeats Viking invaders, but is killed in battle.
- 1348 - The founding of the Order of the Garter by King Edward III of England was announced (it was St George's Day).
- 1521 - Battle of Villalar: King Charles I of Spain defeats the Comuneros.
- 1533 - The Church of England annuls the marriage between Catherine of Aragon and Henry VIII of England.
- 1597 - The Merry Wives of Windsor is first performed; Queen Elizabeth I of England was in attendance.
- 1660 - Treaty of Oliva between Sweden and Poland.
- 1661 - King Charles II of England, Scotland and Ireland is crowned in Westminster Abbey.
- 1827 - William Rowan Hamilton presented his Theory of systems of rays.
- 1867 - William Lincoln patents the Zoetrope, a machine which shows animated pictures by mounting a strip of drawings in a wheel.
- 1876 - April Uprising in Perushtitsa, Bulgaria
- 1920 - The national council in Turkey denounces the government of Sultan Mehmed VI and announces a temporary constitution.
- 1923 - Ceremonial inauguration of Gdynia Seaport.
- 1932 - Windmill De Adriaan burns down in Haarlem, the Netherlands
- 1933 - The Gestapo is established in Germany.
- 1934 - An FBI raid in northern Wisconsin goes wrong when George Nelson, aka "Baby Face", kills Special Agent H. Carter Baum.
- 1942 - World War II: Baedeker Raids - German bombers hit Exeter, Bath and York, England in retaliation for the British raid on Lübeck.
- 1948 - 1948 Arab-Israeli War: Haifa, the major port of Israel, is captured from Palestinian forces.
- 1954 - Hank Aaron hits his first major league home run.
- 1956 - Elvis Presley makes his first appearance in Las Vegas, Nevada.
- 1967 - Soyuz 1 is launched into orbit, carrying a single cosmonaut, Colonel Vladimir Komarov, who is killed when the spacecraft crashes after returning to earth.
- 1968 - The United Kingdom produces its first decimalised coins, a 5p and a 10p coin.
- 1968 - Vietnam War: Student protesters at Columbia University in New York City take over administration buildings and shut down the university.
- 1971 - The Rolling Stones release the classic album Sticky Fingers
- 1974 - A Pan American World Airways Boeing 707 crashes in Bali, Indonesia killing 107.
- 1975 - Vietnam War: At Tulane University, U.S. President Gerald Ford states that the war is over as far as the United States is concerned.
- 1979 - fighting in London between the Anti-Nazi League and the Metropolitan Police's Special Patrol group results in the death of protestor Blair Peach.
- 1985 - New Coke, a marketing disaster, was introduced.
- 1990 - Namibia becomes the 160th member of the United Nations and the 50th member of the British Commonwealth.
- 1993 - Eritreans vote overwhelmingly for independence from Ethiopia in a United Nations-monitored referendum.
- 1994 - Physicists discover the top quark subatomic particle.
- 2001 - Intel introduces the Pentium 4 Processor.
- 2003 - Beijing closes all schools for two weeks due to the SARS virus.
- 1185 - King Afonso II of Portugal (d. 1233)
- 1516 - Georg Fabricius, German poet, historian and archaeologist (d. 1571)
- 1564 - William Shakespeare, English playwright, actor - traditional birth date, Actual date unknown (d. 1616)
- 1598 - Maarten Tromp, admiral in the Dutch navy (d. 1653)
- 1676 - King Frederick I of Sweden (d. 1751)
- 1720 - The Vilna Gaon
- 1775 - William Turner, painter (d. 1851)
- 1791 - James Buchanan, 15th President of the United States (d. 1868)
- 1792 - John Thomas Romney Robinson, Irish astronomer and physicist (d. 1882)
- 1813 - Stephen A. Douglas, Senator from Illinois, candidate for President of the United States (d. 1861)
- 1823 - Abd-ul-Mejid, future Ottoman sultan (d. 1861)
- 1858 - Max Planck, physicist and recipient of the Nobel Prize in physics 1918 (d. 1947)
- 1861 - Edmund Henry Hynman Allenby, British general (d. 1936)
- 1882 - Albert Coates, British composer (d. 1953)
- 1889 - Karel Doorman, Dutch admiral
- 1891 - Sergei Prokofiev, Soviet composer (d. 1953)
- 1893 - Allen Dulles, CIA director (d. 1969)
- 1893 - Frank Borzage, director (d. 1952)
- 1897 - Lester B. Pearson, fourteenth Prime Minister of Canada (d. 1972)
- 1899 - Dame Ngaio Marsh, author (d. 1982)
- 1901 - E.B. Ford British ecological geneticist (d. 1988)
- 1902 - Halldór Laxness, author (d. 1998)
- 1916 - Bud Wilkinson, American football coach
- 1921 - Warren Spahn, Baseball Hall of Famer (d. 2003)
- 1923 - Dolph Briscoe, former governor of Texas
- 1923 - Avram Davidson, science fiction writer (d. 1993)
- 1926 - Ruth Leuwerik, actress
- 1928 - Shirley Temple (Shirley Temple Black), American actress and politician
- 1932 - Halston, fashion designer (d. 1990)
- 1935 - Bunky Green, jazz musician
- 1936 - Roy Orbison, American singer and musician (d. 1988)
- 1939 - Lee Majors, actor
- 1941 - Paavo Lipponen, Prime Minister of Finland
- 1942 - Sandra Dee, actress
- 1949 - Joyce DeWitt, actress
- 1954 - Michael Moore, filmmaker
- 1955 - Judy Davis, actress
- 1955 - Tony Miles, chess player (d. 2001)
- 1960 - Steve Clark, Def Leppard guitarist
- 1960 - Valerie Bertinelli, actress
- 1961 - George Lopez, actor, comedian
- 1968 - Timothy McVeigh, American terrorist (d. 2001)
- 1972 - Patricia Manterola, Mexican singer
- 1979 - Jaime King, actress
- 1014 - Brian Boru, High King of Ireland during the Battle of Clontarf (b. c. 940)
- 1124 - King Alexander I of Scotland (b. 1078)
- 1616 (Julian calendar) - William Shakespeare, English playwright and actor (b. 1564)
- 1616 (Gregorian calendar) - Miguel Cervantes, Spanish author (b. 1547)
- 1792 - Karl Friedrich Bahrdt, German theologian and adventurer (b. 1741)
- 1850 - William Wordsworth, English poet (b. 1770)
- 1951 - Charles G. Dawes, Vice President of the United States for Calvin Coolidge (b 1865)
- 1975 - William Hartnell, actor (b. 1908)
- 1979 - Blair Peach, anti-fascism campaigner (b. 1946)
- 1983 - Buster Crabbe, Olympics swimming gold medalist, actor
- 1986 - Otto Preminger, film director (b. 1906)
- 1986 - Jim Laker, cricketer (b. 1922
- 1990 - Paulette Goddard, actress
- 1992 - Satyajit Ray, Indian filmmaker (b. 1921)
- 1993 - César Chávez, labor activist (b. 1927)
- 1995 - Howard Cosell, sports journalist (b. 1918)
- 1996 - Pamela L. Travers, author (b. 1899)
- 1997 - Denis Compton, English cricketer (b. 1918)
- 1998 - James Earl Ray, assassin (b. 1928)
- 2002 - Linda Lovelace, pornographic film star (b. 1949)
Holidays and observances
April 22 - April 24 - March 23 - May 23 -- listing of all days
es:23 de abril
eo:23-a de aprilo
pt:23 de Abril
vi:23 tháng 4