December 17 is the 351st day of the year in the Gregorian calendar. There are 14 days remaining until the end of the year.
546 – Siege of Rome: The Ostrogoths under king Totila plunder the city, by bribing the Byzantine garrison.
920 – Romanos I Lekapenos is crowned co-emperor of the underage Constantine VII.
942 – Assassination of William I of Normandy.
1398 – Sultan Nasir-u Din Mehmud's armies in Delhi are defeated by Timur.
1538 – Pope Paul III excommunicates Henry VIII of England.
1583 – Cologne War: Forces under Ernest of Bavaria defeat troops under Gebhard Truchsess von Waldburg at the Siege of Godesberg.
1586 – Go-Yōzei becomes Emperor of Japan.
1718 – War of the Quadruple Alliance: Great Britain declares war on Spain.
1777 – American Revolution: France formally recognizes the United States.
1790 – The Aztec calendar stone is discovered at El Zócalo, Mexico City.
1807 – Napoleonic Wars: France issues the Milan Decree, which confirms the Continental System.
1812 – War of 1812: U.S. forces attack a Lenape village in the Battle of the Mississinewa.
1819 – Simón Bolívar declares the independence of Gran Colombia in Angostura (now Ciudad Bolívar in Venezuela).
1835 – The second Great Fire of New York destroys 50 acres (200,000 square meters) of New York City's Financial District.
1837 – A fire in the Winter Palace of Saint Petersburg kills 30 guards.
1862 – American Civil War: General Ulysses S. Grant issues General Order No. 11, expelling Jews from parts of Tennessee, Mississippi, and Kentucky.
1865 – First performance of the Unfinished Symphony by Franz Schubert.
1892 – First issue of Vogue is published.
1896 – Pittsburgh, Pennsylvania's Schenley Park Casino, which was the first multi-purpose arena with the technology to create an artificial ice surface in North America, is destroyed in a fire.
1903 – The Wright brothers make the first controlled powered, heavier-than-air flight in the Wright Flyer at Kitty Hawk, North Carolina.
1907 – Ugyen Wangchuck is crowned first King of Bhutan
1913 – A spur of the Shaker Heights streetcar line opens, the first line of the eventual Cleveland RTA Rapid Transit system.
1918 – Darwin Rebellion: Up to 1,000 demonstrators march on Government House in Darwin, Northern Territory, Australia.
1919 – Uruguay becomes a signatory to the Buenos Aires copyright treaty.
1926 – Antanas Smetona assumes power in Lithuania as the 1926 coup d'état is successful.
1927 – Indian revolutionary Rajendra Lahiri is hanged in Gonda jail, Uttar Pradesh, India, two days before the scheduled date.
1928 – Indian revolutionaries Bhagat Singh, Sukhdev Thapar and Shivaram Rajguru assassinate British police officer James Saunders in Lahore, Punjab, to avenge the death of Lala Lajpat Rai at the hands of the police. The three were executed in 1931.
1935 – First flight of the Douglas DC-3.
1938 – Otto Hahn discovers the nuclear fission of the heavy element uranium, the scientific and technological basis of nuclear energy.
1939 – World War II: Battle of the River Plate: The Admiral Graf Spee is scuttled by Captain Hans Langsdorff outside Montevideo.
1941 – World War II: Japanese forces land in Northern Borneo.
1943 – All Chinese are again permitted to become citizens of the United States upon the repeal of the Act of 1882 and the introduction of the Magnuson Act.
1944 – World War II: Battle of the Bulge: Malmedy massacre: American 285th Field Artillery Observation Battalion POWs are shot by Waffen-SS Kampfgruppe Joachim Peiper.
1947 – First flight of the Boeing B-47 Stratojet strategic bomber.
1948 – The Finnish Security Police is established to remove communist leadership from its predecessor, the State Police.
1950 – The F-86 Sabre's first mission over Korea.
1951 – The American Civil Rights Congress delivers "We Charge Genocide" to the United Nations.
1957 – The United States successfully launches the first Atlas intercontinental ballistic missile at Cape Canaveral, Florida.
1960 – Troops loyal to Emperor Haile Selassie in Ethiopia crush the coup that began December 13, returning power to their leader upon his return from Brazil. Haile Selassie absolves his son of any guilt.
1960 – Munich C-131 crash: Twenty passengers and crew on board as well as 32 people on the ground are killed.
1961 – Niterói circus fire: Fire breaks out during a performance by the Gran Circus Norte-Americano in the city of Niterói, Rio de Janeiro, Brazil, killing more than 500.
1967 – Harold Holt, Prime Minister of Australia, disappears while swimming near Portsea, Victoria, and is presumed drowned.
1969 – Project Blue Book: The United States Air Force closes its study of UFOs.
1970 – 1970 Polish protests: In Gdynia, soldiers fire at workers emerging from trains, killing dozens.
1973 – Thirty passengers are killed in an attack by Palestinian terrorists on Rome's Leonardo da Vinci–Fiumicino Airport.
1981 – American Brigadier General James L. Dozier is abducted by the Red Brigades in Verona, Italy.
1983 – Provisional IRA members detonate a car bomb at Harrods Department Store in London. Three police officers and three civilians are killed.
1989 – Romanian Revolution: Protests continue in Timișoara, Romania, with rioters breaking into the Romanian Communist Party's District Committee building and attempting to set it on fire.
1989 – Fernando Collor de Mello defeats Luiz Inácio Lula da Silva in the second round of the Brazilian presidential election, becoming the first democratically elected President in almost 30 years.
1989 – The Simpsons first premieres on television with the episode "Simpsons Roasting on an Open Fire".
2002 – Second Congo War: The Congolese parties of the Inter Congolese Dialogue sign a peace accord which makes provision for transitional governance and legislative and presidential elections within two years.
2003 – The Soham murder trial ends at the Old Bailey in London, with Ian Huntley found guilty of two counts of murder. His girlfriend, Maxine Carr, is found guilty of perverting the course of justice.
2003 – SpaceShipOne, piloted by Brian Binnie, makes its first powered and first supersonic flight.
2005 – Anti-World Trade Organization protesters riot in Wan Chai, Hong Kong.
2005 – Jigme Singye Wangchuck abdicates the throne as King of Bhutan.
2009 – MV Danny F II sinks off the coast of Lebanon, resulting in the deaths of 44 people and over 28,000 animals.
2010 – Mohamed Bouazizi sets himself on fire. This act became the catalyst for the Tunisian Revolution and the wider Arab Spring.
2014 – The United States and Cuba re-establish diplomatic relations after severing them in 1961.
