September 23 events in history

1122 Pope Callixtus II and Holy Roman Emperor Henry V agree to the Concordat of Worms to put an end to the Investiture Controversy
1338 The Battle of Arnemuiden was the first naval battle of the Hundred Years' War and the first naval battle using artillery, as the English ship Christofer had three cannon and one hand gun
1409 Battle of Kherlen, the second significant victory over Ming China by the Mongols since 1368
1459 Battle of Blore Heath, the first major battle of the English Wars of the Roses, is fought at Blore Heath in Staffordshire
1568 Spanish naval forces rout an English fleet, under the command of John Hawkins, at the Battle of San Juan de Ulúa near Veracruz
1641 The Merchant Royal, carrying a treasure worth over a billion US dollars, is lost at sea off Land's End
1642 First commencement exercises occur at Harvard College
1779 American Revolution: John Paul Jones on board the USS Bonhomme Richard wins the Battle of Flamborough Head
1780 American Revolution: British Major John André is arrested as a spy by American soldiers exposing Benedict Arnold's change of sides
1803 Second Anglo-Maratha War: Battle of Assaye between the British East India Company and the Maratha Empire in India
1806 Lewis and Clark return to St. Louis after exploring the Pacific Northwest of the United States
1821 Tripolitsa, Greece, is captured by Greek rebels during the Greek War of Independence
1845 The Knickerbockers Baseball Club, the first baseball team to play under the modern rules, is founded in New York
1846 Astronomers Urbain Jean Joseph Le Verrier, John Couch Adams and Johann Gottfried Galle collaborate on the discovery of Neptune
1868 Grito de Lares ("Lares Revolt") occurs in Puerto Rico against Spanish rule
1889 Nintendo Koppai (Later Nintendo Company, Limited) is founded by Fusajiro Yamauchi to produce and market the playing card game Hanafuda
1899 American Asiatic Squadron destroys a Filipino battery at the Battle of Olongapo
1905 Norway and Sweden sign the "Karlstad treaty", peacefully dissolving the Union between the two countries
1908 University of Alberta in Alberta, Canada, is founded
1909 The Phantom of the Opera (original title: Le Fantôme de l'Opéra), a novel by French writer Gaston Leroux, is first published as a serialization in Le Gaulois
1911 Pilot Earle Ovington makes the first official airmail delivery in America under the authority of the United States Post Office Department
1913 Roland Garros of France becomes the first to fly in an airplane across the Mediterranean (from St. Raphael France to Bizerte, Tunisia)
1932 The Kingdom of Hejaz and Nejd is renamed the Kingdom of Saudi Arabia
1936 First ascent of Siniolchu by a German team
1938 Mobilization of the Czechoslovak army in response to the Munich Crisis
1942 World War II: The Matanikau action on Guadalcanal begins U.S. Marines attack Japanese units along the Matanikau River
1943 World War II: The Nazi puppet state the Italian Social Republic is founded
1950 Korean War: The Battle of Hill 282 the first US friendly-fire incident on British military personnel since World War II occurred
1952 Richard Nixon makes his "Checkers speech"
1959 Iowa farmer and corn breeder Roswell Garst hosts Soviet premier Nikita Khrushchev
1959 The MS Princess of Tasmania, Australia's first passenger roll-on/roll-off diesel ferry, makes her maiden voyage across Bass Strait
1962 The Lincoln Center for the Performing Arts opens in New York City
1969 The Chicago Eight trial opens in Chicago
1973 Juan Perón returns to power in Argentina
1983 Saint Kitts and Nevis joins the United Nations
1983 Gerrie Coetzee of South Africa becomes the first African boxing world heavyweight champion
1983 Gulf Air Flight 771 is bombed, killing all 117 people on board
1986 Jim Deshaies of the Houston Astros sets the major-league record by striking out the first eight batters of the game against the Los Angeles Dodgers. This record was tied by Jacob deGrom of the New York Mets on September 15, 2014 against the Miami Marlins
1988 José Canseco of the Oakland Athletics becomes the first member of the 40–40 club
1992 A large Provisional Irish Republican Army bomb destroys forensic laboratories in Belfast
1999 Celebrate Bisexuality Day was first observed in the United States
1999 NASA announces that it has lost contact with the Mars Climate Orbiter
2002 The first public version of the web browser Mozilla Firefox ("Phoenix 0.1") is released
2004 Hurricane Jeanne: At least 1,070 in Haiti are reported to have been killed by floods
2008 Kauhajoki school shooting: Matti Saari kills 10 people before committing suicide