- September 18, 0096 Nerva is proclaimed Roman Emperor after Domitian is assassinated.
- September 18, 0335 Dalmatius is raised to the rank of Caesar by his uncle Constantine I.
- September 18, 1180 Philip Augustus becomes king of France.
- September 18, 1356 “In the Battle of Poitiers, the English defeat the French.”
- September 18, 1454 “In the Battle of Chojnice, the Polish army is defeated by Teutonic army during the Thirteen Years’ War.”
- September 18, 1544 Charles V of Germany and Francis I of France sign peace treaty (Truce of Crepy-en-Laonnois)
- September 18, 1573 Spanish attack on Alkmaar.
- September 18, 1615 “Thomas Row, the first British messenger came to India.”
- September 18, 1679 New Hampshire becomes a county of the Massachusetts Bay Colony.
- September 18, 1692 Giles Corey is pressed to death after refusing to plead in the Salem witch trials.
- September 18, 1739 “The Treaty of Belgrade is signed, ceding Belgrade to the Ottoman Empire.”
- September 18, 1739 Treaty of Belgrade-Austria cedes Belgrade to Turks
- September 18, 1755 “Fort Ticonderoga, NY opens”
- September 18, 1759 British capture Québec during the French & Indian War
- September 18, 1759 The British capture Quebec City.
- September 18, 1769 Boston Gazette reports first US piano (a spinet)
- September 18, 1777 First Battle of Saratoga/Battle of Freeman’s Farm/Battle of Bemis Heights.
- September 18, 1789 “American government takes out first ever loan, a total of $191,608.81.”
- September 18, 1796 George Washington’s farewell address is printed across America as an open letter to the public.
- September 18, 1809 Royal Opera House in London opens.
- September 18, 1810 Chile declares independence from Spain (National Day)
- September 18, 1810 “First Government Junta in Chile. Though supposed to rule only in the absence of the king, it was in fact the first step towards independence from Spain, and it is commemorated as such.”
- September 18, 1812 “Fire of Moscow (1812) fades down after destroying more than three quarters of the city. Napoleon returns from Petrovsky Palace to Moscow Kremlin, spared from the fire.”
- September 18, 1830 A horse beats the first U.S.-made locomotive in a race near Baltimore.
- September 18, 1837 “Tiffany and Co. (first named Tiffany & Young) is founded by Charles Lewis Tiffany and John B. Young in New York City, New York. The store was called a “”stationery and fancy goods emporium””.”
- September 18, 1838 Anti-Corn Law League established by Richard Cobden.
- September 18, 1851 NY Times starts publishing
- September 18, 1851 “The New-York Daily Times, which will become The New York Times, begins publishing.”
- September 18, 1872 King Oscar II accedes to the throne of Sweden-Norway.
- September 18, 1873 The Panic of 1873 begins.
- September 18, 1879 Blackpool Illuminations were switched on for the first time.
- September 18, 1885 Riots break out in Montreal to protest compulsory smallpox vaccination.
- September 18, 1893 “Women’s suffrage: In New Zealand, the Electoral Act of 1893 is consented to by the governor giving all women in New Zealand the right to vote.”
- September 18, 1895 “Booker T Washington delivers “”Atlanta Compromise”” address”
- September 18, 1895 “D.D. Palmer of Davenport, Iowa, becomes first chiropractor”
- September 18, 1895 Daniel David Palmer gives the first chiropractic adjustment.
- September 18, 1898 “Fashoda Incident – Lord Kitchener’s ships reach Fashoda, Sudan.”
- September 18, 1900 Butch Cassidy and the Sundance Kid commit their first robbery together.
- September 18, 1906 “A typhoon with tsunami kills an estimated 10,000 people in Hong Kong.”
- September 18, 1910 “In Amsterdam, 25,000 demonstrate for general suffrage.”