333 – Roman Emperor Constantine the Great elevates his youngest son Constans to the rank of Caesar.
336 – First documentary sign of Christmas celebration in Rome.
800 – The Coronation of Charlemagne as Holy Roman Emperor, in Rome.
820 – Emperor Leo V is assassinated in the Hagia Sophia at Constantinople and is succeeded by Michael II.
1000 – The foundation of the Kingdom of Hungary: Hungary is established as a Christian kingdom by Stephen I of Hungary.
1066 – William the Conqueror, Duke of Normandy is crowned king of England, at Westminster Abbey, London.
1559 – Pope Pius IV is elected.
1643 – Christmas Island in the Indian Ocean is found and named by Captain William Mynors of the English East India Company vessel, the Royal Mary.
1776 – George Washington and the Continental Army cross the Delaware River at night to attack Hessian forces serving Great Britain at Trenton, New Jersey, the next day.
1809 – Dr. Ephraim McDowell performs the first ovariotomy, removing a 22-pound tumor.
1815 – The Handel and Haydn Society, oldest continually performing arts organization in the United States, gives its first performance.
1831 – The Great Jamaican Slave Revolt begins; up to 20% of the island’s slaves mobilize in an ultimately unsuccessful fight for freedom.
1926 – Emperor Taishō of Japan dies. His son, Prince Hirohito, succeeds him as Emperor Shōwa.
1927 – The Vietnamese Nationalist Party is founded.
1941 – World War II: Battle of Hong Kong ends, beginning the Japanese occupation of Hong Kong.
1946 – The first European self-sustaining nuclear chain reaction is initiated within the Soviet Union’s F-1 nuclear reactor.
1947 – The Constitution of the Republic of China goes into effect.
1962 – The Soviet Union conducts its final above-ground nuclear weapon test, in anticipation of the 1963 Partial Nuclear Test Ban Treaty.
1968 – Apollo program: Apollo 8 performs the very first successful Trans-Earth injection (TEI) maneuver, sending the crew and spacecraft on a trajectory back to Earth from Lunar orbit.
1968 – Kilvenmani massacre, 44 Dalits (untouchables) are burnt to death in Kizhavenmani village, Tamil Nadu, a retaliation for a campaign for higher wages by Dalit laborers.
1989 – Deposed President of Romania Nicolae Ceaușescu and his wife, First-Deputy Prime-Minister Elena are condemned to death and executed after a summary trial.
1991 – Mikhail Gorbachev resigns as President of the Soviet Union (the union itself is dissolved the next day). Ukraine’sreferendum is finalized and Ukraine officially leaves the Soviet Union.
2004 – The Cassini orbiter releases Huygens probe which successfully landed on Saturn’s moon Titan on January 14, 2005.