October 17 is the 290th day of the year (291st in leap years) in the Gregorian calendar. There are 75 days remaining until the end of the year.
* 539 BC – King Cyrus The Great of Persia marches into the city of Babylon, releasing the Jews from almost 70 years of exile and making the first Human Rights Declaration.
* 1091 – T8/F4 tornado strikes the heart of London.
* 1346 – Battle of Neville's Cross: King David II of Scotland is captured by Edward III of England near Durham, and imprisoned in the Tower of London for eleven years.
* 1448 – Second Battle of Kosovo, where the mainly Hungarian army led by John Hunyadi is defeated by an Ottoman army led by Sultan Murad II.
* 1456 – The University of Greifswald is established, making it the second oldest university in northern Europe (also for a period the oldest in Sweden, and Prussia)
* 1604 – Kepler's Star: German astronomer Johannes Kepler observes a supernova in the constellation Ophiuchus.
* 1610 – French king Louis XIII is crowned in Rheims.
* 1660 – Nine Regicides, the men who signed the death warrant of Charles I, are hanged, drawn and quartered.
* 1662 – Charles II of England sells Dunkirk to France for 40,000 pounds.
* 1771 – Premiere in Milan of the opera Ascanio in Alba, composed by Wolfgang Mozart, age 15.
* 1777 – American troops defeat the British in the Battle of Saratoga.
* 1781 – General Charles Cornwallis offers his surrender to the American revolutionists at Yorktown, Virginia.
* 1797 – Treaty of Campo Formio is signed between France and Austria
* 1800 – England takes control of the Dutch colony of Curaçao.
* 1806 – Former leader of the Haitian Revolution, Emperor Jacques I of Haiti is assassinated after an oppressive rule.
* 1814 – London Beer Flood occurs in London, killing nine.
* 1860 – First The Open Championship (referred to in North America as the British Open).
* 1888 – Thomas Edison files a patent for the Optical Phonograph (the first movie).
* 1907 – Guglielmo Marconi's company begins the first commercial transatlantic wireless service between Glace Bay, Nova Scotia, Canada and Clifden, Ireland.
* 1912 – Bulgaria, Greece and Serbia declare war on the Ottoman Empire, joining Montenegro in the First Balkan War.
* 1917 – First British bombing of Germany in World War I.
* 1931 – Al Capone convicted of income tax evasion.
* 1933 – Albert Einstein, fleeing Nazi Germany, moves to the U.S..
* 1941 – For the first time in World War II, a German submarine attacks an American ship.
* 1941 – German troops execute the male population of the villages Kerdyllia in Serres, Greece and burn the houses down.
* 1943 – Burma Railway (Burma-Thailand Railway) is completed.
* 1945 – A massive number of people, headed by CGT and Evita, gather in the Plaza de Mayo in Argentina to demand Juan Peron's release. This is known to the Peronists as the Día de la lealtad (Loyalty Day). It's considered the founding day of Peronism.
* 1956 – The first commercial nuclear power station is officially opened by Queen Elizabeth II in Sellafield,in Cumbria, England.
* 1961 – Scores of Algerian protesters (some claim up to 400) are massacred by the Paris police at the instigation of Nazi collaborator Maurice Papon, then chief of the Prefecture of Police.
* 1964 – Prime Minister of Australia Robert Menzies opens the artificial Lake Burley Griffin in the middle of the capital Canberra.
* 1965 – The 1964-1965 New York World's Fair closes after a two year run. More than 51 million people had attended the two-year event.
* 1966 – A fire at a building in New York, New York kills 12 firefighters, the New York City Fire Department's deadliest day until the September 11, 2001 attacks.
* 1966 – Botswana and Lesotho join the United Nations.
* 1970 – Montreal, Quebec: Quebec Vice-Premier and Minister of Labour Pierre Laporte murdered by members of the FLQ terrorist group.
* 1973 – OPEC starts an oil embargo against a number of western countries, considered to have helped Israel in its war against Syria.
* 1977 – German Autumn: Four days after it is hijacked, Lufthansa Flight 181 lands in Mogadishu, Somalia, where a team of German GSG 9 commandos later rescues all remaining hostages on board.
* 1979 – Mother Teresa awarded the Nobel Peace Prize.
* 1979 – The Department of Education Organization Act is signed into law creating the US Department of Education and US Department of Health and Human Services.
* 1987 – First commemoration of the International Day for the Eradication of Poverty.
* 1989 – 1989 Loma Prieta earthquake (7.1 on the Richter scale) hits the San Francisco Bay Area and causes 57 deaths directly (and 6 indirectly).
* 1998 – At Jesse, in the Niger Delta, Nigeria, a petroleum pipeline explodes killing about 1200 villagers, some of whom are scavenging gasoline.
* 2000 – Train crash at Hatfield, north of London, leading to collapse of Railtrack.
* 2003 – The pinnacle is fitted on the roof of Taipei 101, a 101-floor skyscraper in Taipei, allowing it to surpass the Petronas Twin Towers in Kuala Lumpur by 50 meters (165 feet) and become the World's tallest highrise.
* 2006 – The United States population reaches 300 million.