AD 81 – Domitian becomes Emperor of the Roman Empire upon the death of his brother Titus.
629 – Emperor Heraclius enters Constantinople in triumph after his victory over the Persian Empire.
786 – “Night of the three Caliphs”: Harun al-Rashid becomes the Abbasid caliph upon the death of his brother al-Hadi. Birth of Harun’s son al-Ma’mun.
919 – Battle of Islandbridge: High King Niall Glúndub is killed while leading an Irish coalition against the Vikings of Uí Ímair, led by King Sitric Cáech.
1180 – Battle of Ishibashiyama in Japan.
1402 – Battle of Homildon Hill results in an English victory over Scotland.
1607 – Flight of the Earls from Lough Swilly, Donegal, Ireland.
1682 – Bishop Gore School, one of the oldest schools in Wales, is founded.
1723 – Grand Master António Manoel de Vilhena lays down the first stone of Fort Manoel in Malta.
1741 – George Frideric Handel completes his oratorio Messiah.
1752 – The British Empire adopts the Gregorian calendar, skipping eleven days (the previous day was September 2).
1763 – Seneca warriors defeat British forces at the Battle of Devil’s Hole during Pontiac’s War.
1791 – The Papal States lose Avignon to Revolutionary France.
1808 – Finnish War: Russians defeat the Swedes at the Battle of Oravais.
1812 – Napoleonic Wars: The French Grande Armée enters Moscow. The Fire of Moscow begins as soon as Russian troops leave the city.
1814 – Battle of Baltimore: The poem Defence of Fort McHenry is written by Francis Scott Key. The poem is later used as the lyrics of The Star-Spangled Banner.
1829 – The Ottoman Empire signs the Treaty of Adrianople with Russia, thus ending the Russo-Turkish War.
1846 – Jang Bahadur and his brothers massacre about 40 members of the Nepalese palace court.
1862 – American Civil War: The Battle of South Mountain, part of the Maryland Campaign, is fought.
1901 – U.S. President William McKinley dies after an assassination attempt on September 6, and is succeeded by Vice President Theodore Roosevelt.
1914 – HMAS AE1, the Royal Australian Navy’s first submarine, was lost at sea with all hands near East New Britain, Papua New Guinea.
1917 – Russia is officially proclaimed a republic.
1936 – Raoul Villain, who assassinated the French Socialist Jean Jaures, is himself killed by Spanish Republicans in Ibiza
1939 – World War II: The Estonian military boards the Polish submarine ORP Orzeł in Tallinn, sparking a diplomatic incident that the Soviet Union will later use to justify the annexation of Estonia.
1940 – Ip massacre: The Hungarian Army, supported by local Hungarians, kill 158 Romanian civilians in Ip, Sălaj, a village in Northern Transylvania, an act of ethnic cleansing.
1943 – World War II: The Wehrmacht starts a three-day retaliatory operation targeting several Greek villages in the region of Viannos, whose death toll would eventually exceed 500 persons.
1944 – World War II: Maastricht becomes the first Dutch city to be liberated by allied forces.
1954 – In a top secret nuclear test, a Soviet Tu-4 bomber drops a 40 kiloton atomic weapon just north of Totskoye village.
1958 – The first two German post-war rockets, designed by the German engineer Ernst Mohr, reach the upper atmosphere.
1959 – The Soviet probe Luna 2 crashes onto the Moon, becoming the first man-made object to reach it.
1960 – The Organization of Petroleum Exporting Countries (OPEC) is founded.
1960 – Congo Crisis: With CIA help, Mobutu Sese Seko seizes power in a military coup, suspending parliament and the constitution.
1969 – The US Selective Service selects September 14 as the First Draft Lottery date.
1975 – The first American saint, Elizabeth Ann Seton, is canonized by Pope Paul VI.
1979 – Afghan President Nur Muhammad Taraki is assassinated upon the order of Hafizullah Amin, who becomes the new president.
1982 – President-elect of Lebanon, Bachir Gemayel, is assassinated.
1984 – Joe Kittinger becomes the first person to fly a gas balloon alone across the Atlantic Ocean.
1985 – Penang Bridge, the longest bridge in Malaysia, connecting the island of Penang to the mainland, opens to traffic.
1992 – The Constitutional Court of Bosnia and Herzegovina declares the breakaway Croatian Republic of Herzeg-Bosnia to be illegal.
1994 – The Major League Baseball season is canceled because of a strike.
1997 – 81 killed as five bogies of the Ahmedabad–Howrah Express plunge into a river in Bilaspur district of Madhya Pradesh, India.
1998 – Telecommunications companies MCI Communications and WorldCom complete their $37 billion merger to form MCI WorldCom.
1999 – Kiribati, Nauru and Tonga join the United Nations.
2000 – Microsoft releases Windows ME.
2001 – Historic National Prayer Service held at Washington National Cathedral for victims of the September 11 attacks. A similar service is held in Canada on Parliament Hill, the largest vigil ever held in the nation’s capital.
2003 – In a referendum, Estonia approves joining the European Union.
2007 – Late-2000s financial crisis: The Northern Rock bank experiences the first bank run in the United Kingdom in 150 years.
2015 – The first observation of gravitational waves was made, announced by the LIGO and Virgo collaborations on 11 February 2016.