- September 12, 0490 BC – Athens defeats Persia at the Battle of Marathon – see also 12 August; origin of the marathon long-distance race (attributed to Pheidippides)
- September 12, 0490 -BC- Athenians defeat 2nd Persian invasion of Greece at Marathon
- September 12, 1213 “Albigensian Crusade: Simon de Montfort, 5th Earl of Leicester defeats Peter II of Aragon, the king of Aragon at the Battle of Muret.”
- September 12, 1229 “The Aragonese army under the command of James I of Aragon disembarks at Santa Pona, Mallorca, with the purpose of conquering the island.”
- September 12, 1649 “Drogheda, Ireland falls to Puritan troops; inhabitants massacred”
- September 12, 1683 Austro-Ottoman War: Battle of Vienna – Several European armies join forces to defeat the Ottoman Empire.
- September 12, 1695 NY Jews petition governor Dongan for religious liberties
- September 12, 1758 Charles Messier observes the Crab Nebula and begins catalog
- September 12, 1814 Battle of North Point fought near Baltimore during War of 1812
- September 12, 1814 Battle of North Point: An American detachment halts the British land advance to Baltimore in the War of 1812.
- September 12, 1846 Elizabeth Barrett elopes with Robert Browning.
- September 12, 1848 Switzerland became a Federal state.
- September 12, 1857 “423 die when the ship named “”Central America”” sinks off Cape Romain SC”
- September 12, 1857 “The SS Central America sinks about 160 miles east of Cape Hatteras, North Carolina, drowning a total of 426 passengers and crew, including Captain William Lewis Herndon. The ship carried 13-15 tons of gold from the San Francisco Gold Rush.”
- September 12, 1874 “e District of Maple Ridge, British Columbia, Canada is founded.”
- September 12, 1874 “The District of Maple Ridge, British Columbia, Canada is founded.”
- September 12, 1890 Salisbury is founded by the British South Africa Company in the Mashonaland territory that will become Rhodesia
- September 12, 1890 “Salisbury, Rhodesia, is founded.”
- September 12, 1895 Defender (US) beats Valkyrie III (England) in 10th America’s Cup
- September 12, 1897 Battle of Saragarhi
- September 12, 1901 Arabs attack Gedara Palestine
- September 12, 1906 “Newport Transporter Bridge is opened in Newport, South Wales by Viscount Tredegar.”
- September 12, 1910 “Premiere performance of Gustav Mahler’s 8th symphony in Munich (with a chorus of 852 singers, with an orchestra of 171 players. Mahler’s rehearsal assistant conductor was Bruno Walter)”
- September 12, 1918 “During WW I, US forces launch an attack on German-occupied St Mihiel”
- September 12, 1918 “Sgt. Henry John Laurent, 3rd NZ (Rifle) Brigade, won the Victoria Cross at Gouzeacourt Wood France”
- September 12, 1920 7th Olympic games close in Antwerp Belgium
- September 12, 1923 Britain takes over Southern Rhodesia from British South Africa Co
- September 12, 1928 “Katharine Hepburn’s NY stage debut in “”Night Hostess”””
- September 12, 1930 Wilfred Rhodes ends his 1110-game first-class career by taking 5 for 95 for H.D.G. Leveson Gower’s XI against the Australians.
- September 12, 1933 “Le Szilrd, waiting for a red light on Southampton Row in Bloomsbury, conceives the idea of the nuclear chain reaction.”
- September 12, 1933 “Leó Szilárd, waiting for a red light on Southampton Row in Bloomsbury, conceives the idea of the nuclear chain reaction.”
- September 12, 1934 “Baltic Pact signed by Lithuania, Estonia and Latvia”
- September 12, 1938 Adolf Hitler demands autonomy for the Germans of the Sudetenland region of Czechoslovakia.
- September 12, 1938 Adolph Hitler demands self-determination for Sudeten Germans in Czech
- September 12, 1940 49 die and 200 injured when Hercules Powder Co plant explodes (NJ)
- September 12, 1940 “Cave paintings discovered in Lascaux, France.”
- September 12, 1940 “The Hercules Powder Company in Kenvil, New Jersey explodes, killing 51 people and injuring over 200.”
- September 12, 1941 First German ship in WW2 captured by US ship (Busko)
- September 12, 1942 World War II: First day of the Battle of Edson’s Ridge during the Guadalcanal campaign. U.S. Marines protecting Henderson Field on Guadalcanal are attacked by Imperial Japanese Army forces.
- September 12, 1942 “World War II: RMS Laconia, carrying civilians, Allied soldiers and Italian POWs is torpedoed off the coast of West Africa and sinks.”