October 21 is the 294th day of the year (295th in leap years) in the Gregorian calendar. There are 71 days remaining until the end of the year.
686 – Conon becomes Pope.
1096 - People's Crusade: The Turkish army heavily defeats the People's Army of the West.
1097 - First Crusade: The Siege of Antioch begins.
1209 - Otto IV, Holy Roman Emperor is crowned by Pope Innocent III.
1392 - Emperor Kameyama of Japan abdicates the throne in favour of his arch-rival Emperor Go-Komatsu.
1512 - Martin Luther joins the theological faculty at the University of Wittenberg.
1520 - Ferdinand Magellan enters what is now known as the Magellan Strait.
1600 – Tokugawa Ieyasu defeats the leaders of rival Japanese clans in the Battle of Sekigahara, which marks the beginning of the Tokugawa shogunate, who in effect rule Japan until the mid-Nineteenth century.
1638 - In England, the church at Widecombe-on-the-Moor is struck by lightning during an afternoon service, leading to new scientific research on lightning strikes.
1797 – In Boston Harbor, the 44-gun United States Navy frigate USS is launched. Constitution
1805 – Napoleonic Wars: Battle of Trafalgar – a British fleet led by Admiral Lord Nelson defeats a combined French and Spanish fleet off the coast of Spain under Admiral Villeneuve. It signalled the virtual end of French maritime power and left Britain navally unchallenged until the twentieth century.
1805 – Napoleonic Wars: Austrian General Mack surrendurs his army to the Grand Armee of Napoleon at Ulm, reaping Napoleon over 30,000 prisoners and inflicting 10,000 casualties on the losers. Ulm was considered to be one of Napoleon's finest hours.
1816 - The Penang Free School is founded in George Town, Malaysia. It is the oldest English language school in Southeast Asia.
1824 – Joseph Aspdin patents Portland cement.
1854 – Florence Nightingale and a staff of 38 nurses were sent to the Crimean War.
1861 – American Civil War: Battle of Ball's Bluff – Union forces under Colonel Edward Baker are defeated by Confederate troops in the second major battle of the war. Baker, a close friend of Abraham Lincoln, is killed in the fighting.
1867 – Manifest Destiny: Medicine Lodge Treaty – Near Medicine Lodge Creek, Kansas a landmark treaty is signed by southern Great Plains Indian leaders. The treaty requires Native American Plains tribes to relocate a reservation in western Oklahoma.
1879 – Using a filament of carbonized thread, Thomas Edison tests the first practical electric light bulb (it lasted 13 1/2 hours before burning out).
1885 - In an assassination attempt, Danish Prime Minister Jacob Estrup is shot.
1888 - The Swiss Social Democratic Party is founded.
1895 – The Republic of Taiwan collapses as Japanese forces invade.
1902 – In the United States, a five month strike by United Mine Workers ends.
1907 - A magnitude 8.1 earthquake hits Central Asia, killing 12,000.
1910 - HMS Niobe arrives at Halifax Harbour, Nova Scotia to become the first ship of the Royal Canadian Navy.
1921 – US President Warren G. Harding delivers the first speech by a sitting President against lynching in the deep south.
1930 - A mining disaster at Alsdorf, near Aachen, Germany, kills 271 people.
1934 – Mao Tse-tung and his followers begin the Long March.
1941 – World War II: Germans rampage in Yugoslavia, killing thousands of civilians.
1943 - The Provisional Government of Free India is declared by Subhas Chandra Bose.
1944 – The first kamikaze attack: HMAS Australia was hit by a Japanese plane carrying a 200 kg (441 pound) bomb off Leyte Island, as the Battle of Leyte Gulf began.
1944 - World War II: Aachen becomes the first major German city to fall to the Allies.
1945 – Women's suffrage: Women are allowed to vote in France for the first time.
1945 – Argentine military officer and politician Juan Perón married actress Evita.
1947 – 21 die as a fire destroys an asylum in Hoff, Germany.
1948 - A Lockheed Constellation airplane crashes at Prestwick, Scotland, killing 39 people.
1957 – The movie Jailhouse Rock, starring Elvis Presley, opens.
1959 – In New York City, the Solomon R. Guggenheim Museum opens to the public. It was designed by Frank Lloyd Wright.
1959 – US President Dwight D. Eisenhower signs an executive order transferring Wernher von Braun and other German scientists from the United States Army to NASA.
1962 - Norwegian postal ship Sanct Svithun sinks, killing 41.
1965 - Comet Ikeya-Seki approaches Perihelion, passing 200,000 kilometers (279,617 miles) within Earth.
1966 – Aberfan disaster: A coal tip falls on the village of Aberfan in Wales, killing 144 people, mostly schoolchildren
1967 – Vietnam War: More than 100,000 war protesters gather in Washington, DC. A peaceful rally at the Lincoln Memorial is followed by a march to The Pentagon and clashes with soldiers and United States Marshals protecting the facility (event lasts until October 23; 683 people will be arrested). Similar demonstrations occurred simultaneously in Japan and Western Europe.
1969 - Willy Brandt is elected Chancellor of West Germany.
1971 - 22 people are killed in a gas explosion at a shopping centre in Clarkston, East Renfrewshire, near Glasgow, Scotland.
1973 – John Paul Getty III's ear is cut off by his kidnappers and sent to a newspaper in Rome; it does not arrive until November 8.
1977 - The European Patent Institute is founded.
1980 – 1980 World Series: In 6 games, the Philadelphia Phillies win their first World Series.
1981 - Andreas Papandreou becomes Prime Minister of Greece.
1986 – In Lebanon, pro- Iranian kidnappers claim to have abducted American writer Edward Tracy (he will be released in August 1991).
1987 – Former Miss America Bess Myerson is arrested on charges of bribery, conspiracy, and mail fraud, all involving an alimony-fixing scandal. She is later found not guilty.
1994 – North Korea nuclear weapons program: North Korea and the United States sign an agreement that requires North Korea to stop its nuclear weapons program and agree to inspections.
1994 - In Seoul, South Korea, 32 people are killed when the Seongsu Bridge collapses.
1997 – Hotel owners from the Detroit area meet to discuss Jack Kevorkian's practice of leaving corpses in hotel rooms.
1997 – The government of Singapore announces in a widely-publicized " toilet alert" that the drive for toilet cleanliness is a great success; five toilets were selected by citizens as toilet role models.
1328 - Hongwu Emperor of China (d. 1398)
1449 – George, Duke of Clarence (d. 1478)
1527 - Louis I, Cardinal of Guise (d. 1578)
1581 – Domenico Zampieri, Italian painter (d. 1641)
1650 - Jean Bart, French naval commander (d. 1702)
1660 – Georg Ernst Stahl, German scientist (d. 1734)
1671 – King Frederick IV of Demmark (d. 1730)
1672 - Ludovico Antonio Muratori, Italian writer (d. 1750)
1675 – Emperor Higashiyama of Japan (d. 1710)
1687 – Nicolaus I Bernoulli, Swiss mathematician (d. 1759)
1728 - José Moñino, 1st Count of Floridablanca, Spanish politician (d. 1808)
1762 - Herman Willem Daendels, Dutch statesman (d. 1818)
1772 – Samuel Taylor Coleridge, British poet (d. 1834)
1775 - Giuseppe Baini, Italian composer (d. 1844)
1790 - Alphonse de Lamartine, French writer (d. 1869)
1811 - Filippo Colini, Italian opera singer (d. 1863)
1823 - Emilio Arrieta, Spanish composer (d. 1894)
1833 – Alfred Nobel, Swedish inventor (d. 1896)
1837 - James A. Beaver, 20th Governor of Pennsylvania (d. 1914)
1839 - Georg von Siemens, German banker and politician (d. 1901)
1845 – Will Carleton, American poet (d. 1912)
1847 – Giuseppe Giacosa, Italian writer (d. 1906)
1874 - Henri Guisan, Swiss general (d. 1960)
1884 - Claire Waldoff, German singer and entertainer (d. 1957)
1886 – Eugene Burton Ely, American aviator (d. 1911)
1886 - Karl Polanyi, Austro-Hungarian economist (d. 1964)
1887 - James L. McConaughy, American politician, Governor of Connecticut (d. 1948)
1887 - Krishna Singh, Indian politician, 1st Chief Minister of Bihar (d. 1961)
1892 – Otto Nerz, German footballer and coach (d. 1949)
1894 - Edogawa Rampo, Japanese writer and critic (d. 1965)
1895 - Edna Purviance, American actress (d. 1958)
1895 - Paavo Johansson, Finnish javelin thrower (d. 1983)
1896 - Evgeny Schwarz, Russian movie writer (d. 1958)
1901 - Margarete Buber-Neumann, German politician (d. 1989)
1907 - Nikos Engonopoulos, Greek painter and poet (d. 1985)
1911 – Mary Blair, American artist and illustrator (d. 1978)
1912 – Georg Solti, Hungarian conductor (d. 1997)
1914 – Kazimierz Swiatek, Roman Catholic cardinal of Belarus (d. 2011)
1914 – Martin Gardner, American writer (d. 2010)
1917 – Dizzy Gillespie, American musician (d. 1993)
1918 - Hulett C. Smith, Governor of West Virginia (d. 2012)
1921 – Malcolm Arnold, British composer (d. 2006)
1921 - Ingrid van Houten-Groeneveld, Dutch astronomer (d. 2015)
1921 - Sena Jurinac, Bosnian operatic soprano (d. 2011)
1922 – Liliane Bettencourt, French L'Oreal heiress
1924 - Julie Wilson, American actress (d. 2015)
1925 – Celia Cruz, Cuban Salsa singer (d. 2003)
1925 - Virginia Zeani, Romanian soprano
1926 – Leonard Rossiter, English comedian and actor (d. 1984)
1926 - William Love Waller, Governor of Mississippi (d. 2011)
1927 – Fritz Wintersteller, Austrian mountaineer
1928 - Vern Mikkelsen, American basketball player
1928 - Whitey Ford, American baseball player
1929 - Pierre Bellemare, French writer, radio and television host
1930 - Ivan Stepanovich Silayev, Soviet Prime Minister
1931 – Shammi Kapoor, Indian actor (d. 2011)
1932 - Pal Csernai, Hungarian footballer (d. 2013)
1933 - Georgia Brown, American actress (d. 1992)
1933 - Joan Hinde, English trumpeter and entertainer (d. 2015)
1937 - Said Afandi al-Chirkawi, Russian spiritual leader (d. 2012)
1940 – Geoff Boycott, English cricketer
1940 – Manfred Mann, South African-English musician
1940 - Marita Petersen, Prime Minister of the Faroe Islands (d. 2001)
1941 – Steve Cropper, American musician and songwriter
1942 – Christopher A. Sims, American economist
1942 - Paul Churchland, Canadian philosopher
1942 - Judith Sheindlin, American judge ( Judge Judy)
1942 - Lou Lamoriello, American ice hockey player, coach and manager
1943 – Tariq Ali, Pakistani writer and historian
1944 - Jean-Pierre Sauvage, French chemist, 2016 joint Nobel Prize in Chemistry laureate
1944 - Mandy Rice-Davies, British media personality (d. 2014)
1945 - Nikita Mikhalkov, Soviet-Russian movie director
1946 - Jane Heal, British philosopher
1946 – Lux Interior, American singer (d. 2009)
1948 - Tom Everett, American actor
1949 – Benjamin Netanyahu, Israeli politician and Prime Minister
1949 - LeTanya Richardson, American actress
1949 - Mike Keenan, Canadian ice hockey coach
1950 - Ronald McNair, American astronaut (d. 1986)
1952 - Trevor Chappell, Australian cricketer
1952 – Brent Mydland, American keyboardist (d. 1990)
1952 - Patti Davis, American actress and novelist, daughter of Ronald Reagan
1953 – Peter Mandelson, English politician
1953 - Eric Faulkner, Scottish singer-songwriter and guitarist
1954 - Brian Tobin, Canadian politician
1955 - Catherine Hardwicke, American film director, producer, designer and screenwriter
1956 – Carrie Fisher, American actress and writer
1957 - Steve Lukather, American guitarist and singer ( Toto)
1957 – Wolfgang Ketterle, German physicist, Nobel Prize winner
1958 - Andre Geim, Russian-born physicist, Nobel Prize winner
1959 – Ken Watanabe, Japanese actor
1962 - David Campese, Australian rugby player
1964 – Jon Carin, American musician
1965 – Ion Andoni Goikoetxea, Basque-Spanish footballer
1967 – Paul Ince, English footballer
1969 – Salman bin Hamad bin Isa Al Khalifa, crown prince of Bahrain
1969 - Chris Law, Scottish politician
1971 – Jade Jagger, socialite and jewellery designer
1971 - Paul Telfer, Scottish footballer
1971 - Thomas Ulsrud, Norwegian curler
1972 - Felicity Anderson, Australian actress
1974 - Costel Busuioc, Romanian tenor
1979 - Karl Harris, British motorcycle racer (d. 2014)
1980 – Kim Kardashian, American socialite, model and reality television personality
1981 – Nemanja Vidic, Serbian footballer
1981 - Martin Castrogiovanni, Argentine-born Italian rugby player
1983 – Hrvoje Custic, Croatian footballer (d. 2008)
1983 - Amber Rose, American model
1983 - Charlotte Sullivan, Canadian actress
1984 – Kieran Richardson, English footballer
1986 – Natalee Holloway, American teenager (missing since 2005)
1986 - Tamerlan Tsarnaev, Chechen-American terrorist (d. 2013)
1988 - James White, American basketball player
1989 - Sam Vokes, Welsh footballer
1990 – Ricky Rubio, Spanish basketball player
1992 – Bernard Tomic, Australian tennis player
1995 - Cameron Burgess, Scottish-Australian footballer
1995 - Shannon Magrane, American singer
310 – Pope Eusebius
1125 - Cosmas of Prague, Bohemian writer
1204 - Robert de Beaufort, 4th Earl of Leicester
1221 - Alix, Duchess of Brittany (b. 1201)
1266 – Birger Jarl, Swedish statesman (b. 1210)
1422 – King Charles VI of France (b. 1368)
1500 - Emperor Go-Tsuchimikado of Japan (b. 1442)
1558 – Julius Caesar Scaliger, humanist scholar (b. 1484)
1600 - Toda Katsushige, Japanese warlord (b. 1557)
1623 - William Wade, English statesman and diplomat (b. 1546)
1687 – Sir Edmund Waller, English poet (b. 1606)
1708 - Guru Gobind Singh, 10th Sikh Guru (b. 1666)
1765 – Giovani Paolo Panini, Italian painter and architect (b. 1691)
1775 – Peyton Randolph, American politician, President of the Continental Congress (b. 1721)
1805 - Killed in the Battle of Trafalgar:
1818 – Michael Howe, bushranger in Tasmania, Australia
1821 - Dorothea Ackermann, German actress (b. 1752)
1872 - Jacques Babinet, French physicist (b. 1794)
1873 – Johann Sebastian Welhaven, Norwegian poet (b. 1807)
1896 – James Henry Greathead, British engineer (b. 1844)
1903 - Jinmaku Kyugoro, Japanese sumo wrestler (b. 1829)
1904 - Isabelle Eberhardt, Swiss explorer and writer (b. 1877)
1907 - Jules Chevalier, French priest (b. 1824)
1916 - Count Karl von Stürgkh, Austrian politician (b. 1859)
1931 – Arthur Schnitzler, Austrian writer (b. 1862)
1931 - Barbecue Bob, American blues musician (b. 1902)
1940 - William G. Conley, Governor of West Virginia (b. 1866)
1944 – Alois Kayser, German missionary, working in Nauru
1952 - Hans Merensky, South African geologist and philanthropist (b. 1871)
1967 - Ejnar Hertzsprung, Danish astronomer (b. 1873)
1969 – Waclaw Sierpinski, Polish mathematician (b. 1882)
1969 – Jack Kerouac, American beat novelist (b. 1922)
1975 – Charles Reidpath, American athlete (b. 1887)
1978 – Anastas Mikoyan, Soviet politician (b. 1895)
1980 – Hans Asperger, Austrian psychologist who discovered Asperger's Syndrome (b. 1906).
1984 – François Truffaut, French movie director (b. 1932)
1985 - Dan White, American politician (b. 1946)
1986 – Lionel Murphy, Australian Labor Party politician and High Court judge (b. 1922)
1990 - Walther Sommerlath, German businessman, father of Queen Silvia of Sweden (b. 1901)
1993 – Melchior Ndadaye, President of Burundi (b. 1953)
1995 – Shannon Hoon, lead singer of pop band Blind Melon (b. 1967)
1995 - Maxene Andrews, American singer (b. 1916)
1995 – Jesús Blasco, Spanish comic book writer (b. 1919)
1996 - Georgios Zoitakis, Greek army general and regent (b. 1910)
1998 - Francis W. Sargent, Governor of Massachusetts (b. 1915)
1999 – Lars Bo, Danish artist and writer (b. 1924)
2003 – Fred Berry, American actor (b. 1951)
2003 – Luis A. Ferré, former governor of Puerto Rico (b. 1904)
2003 – Louise Day Hicks, US politician (b. 1916)
2003 – Elliott Smith, American musician (b. 1969)
2006 – Sandy West, American musician (b. 1959)
2010 – Loki Schmidt, German environmentalist and wife of Helmut Schmidt (b. 1919)
2011 - Edmundo Ros, Trinidadian musician (b. 1910)
2012 - George McGovern, American politician (b. 1922)
2012 - Yash Chopra, Indian movie director, screenwriter and producer (b. 1932)
2014 - Gough Whitlam, 21st Prime Minister of Australia (b. 1916)
2014 - Benjamin C. Bradlee, American journalist (b. 1921)
2014 - Mohammad-Reza Mahdavi Kani, Iranian politician and cleric (b. 1931)
2014 - Seth Gaaikema, Dutch comedian and writer (b. 1939)
2014 - Lilli Carati, Italian actress (b. 1956)
2015 - Marty Ingels, American actor (b. 1936)