21December Events

December 21 is the 355th day of the year (356th in leap years) in the Gregorian calendar. There are 10 days remaining until the end of the year. This date is slightly more likely to fall on a Monday, Wednesday or Friday (58 in 400 years each) than on Saturday or Sunday (57), and slightly less likely to occur on a Tuesday or Thursday (56).

In the Northern Hemisphere, December 21st is usually the shortest day of the year and is sometimes regarded as the first day of winter. In the Southern Hemisphere, December 21st is usually the longest day of the year and occurs during the southern summer.
69 – The Roman Senate declares Vespasian emperor of Rome, the last in the Year of the Four Emperors.
1124 – Pope Honorius II is elected.
1140 – Conrad III of Germany besieged Weinsberg.
1237 – The city of Ryazan is sacked by the Mongol army of Batu Khan.
1361 – The Battle of Linuesa is fought in the context of the Spanish Reconquista between the forces of the Emirate of Granada and the combined army of the Kingdom of Castile and of Jaén resulting in a Castilian victory.
1598 – Battle of Curalaba: The revolting Mapuche, led by cacique Pelentaru, inflict a major defeat on Spanish troops in southern Chile.
1620 – Plymouth Colony: William Bradford and the Mayflower Pilgrims land on what is now known as Plymouth Rock in Plymouth, Massachusetts.
1826 – American settlers in Nacogdoches, Mexican Texas, declare their independence, starting the Fredonian Rebellion.
1832 – Egyptian–Ottoman War: Egyptian forces decisively defeat Ottoman troops at the Battle of Konya.
1844 – The Rochdale Society of Equitable Pioneers commences business at its cooperative in Rochdale, England, starting the Cooperative movement.
1861 – Medal of Honor: Public Resolution 82, containing a provision for a Navy Medal of Valor, is signed into law by President Abraham Lincoln.
1872 – Challenger expedition: HMS Challenger, commanded by Captain George Nares, sails from Portsmouth, England.
1879 – World premiere of Henrik Ibsen's A Doll's House at the Royal Theatre in Copenhagen, Denmark.
1883 – The Royal Canadian Dragoons and The Royal Canadian Regiment, the first Permanent Force cavalry and infantry regiments of the Canadian Army, are formed.
1907 – The Chilean Army commits a massacre of at least 2,000 striking saltpeter miners in Iquique, Chile.
1910 – An underground explosion at the Hulton Bank Colliery No. 3 Pit in Over Hulton, Westhoughton, England, kills 344 miners.
1913 – Arthur Wynne's "word-cross", the first crossword puzzle, is published in the New York World.
1919 – American anarchist Emma Goldman is deported to Russia.
1923 – United Kingdom and Nepal formally signed an agreement of friendship, called the Nepal–Britain Treaty of 1923, which superseded the Treaty of Sugauli signed in 1816.
1936 – First flight of the Junkers Ju 88 multi-role combat aircraft.
1937 – Snow White and the Seven Dwarfs, the world's first full-length animated feature, premieres at the Carthay Circle Theatre.
1941 – World War II: A formal treaty of alliance between Thailand and Japan is signed in the presence of the Emerald Buddha in Wat Phra Kaew, Thailand.
1946 – An 8.1 Mw earthquake and subsequent tsunami in Nankaidō, Japan, kills over 1,300 people and destroys over 38,000 homes.
1962 – Rondane National Park is established as Norway's first national park.
1963 – The episode of intercommunal violence called "Bloody Christmas" begins in Cyprus, ultimately resulting in the displacement of 25,000-30,000 Turkish Cypriots and destruction of more than 100 villages.
1967 – Louis Washkansky, the first man to undergo a heart transplant, dies in Cape Town, South Africa, having lived for 18 days after the transplant.
1968 – Apollo program: Apollo 8 is launched from the Kennedy Space Center, placing its crew on a lunar trajectory for the first visit to another celestial body by humans.
1973 – The Geneva Conference on the Arab–Israeli conflict opens.
1979 – Lancaster House Agreement: An independence agreement for Rhodesia is signed in London by Lord Peter Carrington, Sir Ian Gilmour, Robert Mugabe, Joshua Nkomo, Bishop Abel Muzorewa and S.C. Mundawarara.
1988 – A bomb explodes on board Pan Am Flight 103 over Lockerbie, Dumfries and Galloway, Scotland, killing 270.
1992 – A Dutch DC-10, flight Martinair MP 495, crashes at Faro Airport, killing 56.
1994 – Mexican volcano Popocatépetl, dormant for 47 years, erupts gases and ash.
1995 – The city of Bethlehem passes from Israeli to Palestinian control.
1999 – The Spanish Civil Guard intercepts a van loaded with 950 kg of explosives that ETA intended to use to blow up Torre Picasso in Madrid, Spain.
2004 – Iraq War: A suicide bomber killed 22 at the forward operating base next to the main U.S. military airfield at Mosul, Iraq, the single deadliest suicide attack on American soldiers.

Source: Wikipedia