October 23 events in history

425 Valentinian III is elevated as Roman emperor at the age of six
501 The Synodus Palmaris, called by Gothic king Theoderic the Great, discharges Pope Symmachus of all charges, thus ending the schism of Antipope Laurentius
1086 At the Battle of az-Zallaqah, the army of Yusuf ibn Tashfin defeats the forces of Castilian King Alfonso VI
1157 The Battle of Grathe Heath ends the civil war in Denmark. King Sweyn III is killed and Valdemar I restores the country
1295 The first treaty forming the Auld Alliance between Scotland and France against England is signed in Paris
1641 Outbreak of the Irish Rebellion of 1641
1642 Battle of Edgehill: First major battle of the First English Civil War
1694 British/American colonial forces, led by Sir William Phips, fail to seize Quebec from the French
1707 The first Parliament of Great Britain meets
1739 War of Jenkins' Ear starts: British Prime Minister Robert Walpole, reluctantly declares war on Spain
1812 Claude François de Malet, a French general, begins a conspiracy to overthrow Napoleon Bonaparte, claiming that the Emperor died in Russia and that he is now the commandant of Paris
1850 The first National Women's Rights Convention begins in Worcester, Massachusetts, United States
1861 U.S. President Abraham Lincoln suspends the writ of habeas corpus in Washington, D.C., for all military-related cases
1864 American Civil War: Battle of Westport: Union forces under General Samuel R. Curtis defeat Confederate troops led by General Sterling Price at Westport, near Kansas City
1867 Seventy-two Senators are summoned by Royal Proclamation to serve as the first members of the Canadian Senate
1870 Franco-Prussian War: The Siege of Metz concludes with a decisive Prussian victory
1906 Alberto Santos-Dumont flies an airplane in the first heavier-than-air flight in Europe at Champs de Bagatelle, Paris, France
1911 First use of aircraft in war: Italo-Turkish War: An Italian pilot takes off from Libya to observe Turkish army lines
1912 First Balkan War: The Battle of Kumanovo between the Serbian and Ottoman armies begins
1915 Women's suffrage: In New York City, 25,000-33,000 women march on Fifth Avenue to advocate their right to vote
1917 Lenin calls for the October Revolution
1929 Great Depression: After a steady decline in stock market prices since a peak in September, the New York Stock Exchange begins to show signs of panic
1935 Dutch Schultz, Abe Landau, Otto Berman, and Bernard "Lulu" Rosencrantz are fatally shot at a saloon in Newark, New Jersey in what will become known as The Chophouse Massacre
1939 The Japanese Mitsubishi G4M twin-engine "Betty" Bomber makes its maiden flight
1941 World War II: Field Marshal Georgy Zhukov takes command of Red Army operations to prevent the further advance into Russia of German forces and to prevent the Wehrmacht from capturing Moscow
1942 World War II: Second Battle of El Alamein: At El Alamein in northern Egypt, the British Eighth Army under Field Marshal Montgomery begins a critical offensive to expel the Axis armies from Egypt
1942 All 12 passengers and crewmen aboard an American Airlines DC-3 airliner are killed when it is struck by a U.S. Army Air Forces bomber near Palm Springs, California. Amongst the victims is award-winning composer and songwriter Ralph Rainger ("Thanks for the Memory", "Love in Bloom", "Blue Hawaii")
1942 World War II: The Battle for Henderson Field begins during the Guadalcanal Campaign and ends on October 26
1944 World War II: Battle of Leyte Gulf: The largest naval battle in history begins in the Philippines
1946 The United Nations General Assembly convenes for the first time, at an auditorium in Flushing, Queens, New York City
1955 Prime Minister Ngô Đình Diệm defeats former emperor Bảo Đại in a referendum and founds the Republic of Vietnam
1956 Thousands of Hungarians protest against the government and Soviet occupation. (The Hungarian Revolution is crushed on November 4)
1958 The Springhill Mine bump: An underground earthquake traps 174 miners in the No. 2 colliery at Springhill, Nova Scotia, the deepest coal mine in North America at the time. By November 1, rescuers from around the world had dug out 100 of the victims, marking the death toll at 74
1958 The Smurfs, a fictional race of blue dwarves, later popularized in a Hanna-Barbera animated cartoon series, appear for the first time in the story La flute à six schtroumpfs, a Johan and Peewit adventure by Peyo, which is serialized in the weekly Spirou magazine
1965 Vietnam War: The 1st Cavalry Division (United States) (Airmobile), in conjunction with South Vietnamese forces, launches a new operation seeking to destroy North Vietnamese forces in Pleiku in the II Corps Tactical Zone (the Central Highlands)
1970 Gary Gabelich sets a land speed record in a rocket-powered automobile called the Blue Flame, fueled with natural gas
1972 Operation Linebacker, a US bombing campaign against North Vietnam in response to its Easter Offensive, ends after five months
1973 The Watergate scandal: US President Richard M. Nixon agrees to turn over subpoenaed audio tapes of his Oval Office conversations
1973 A United Nations sanctioned cease-fire officially ends the Yom Kippur War between Israel and Syria
1983 Lebanese Civil War: The U.S. Marines barracks in Beirut is hit by a truck bomb, killing 241 U.S. military personnel. A French army barracks in Lebanon is also hit that same morning, killing 58 troops
1989 The Hungarian Republic is officially declared by president Mátyás Szűrös, replacing the communist Hungarian People's Republic
1989 Bankruptcy of Wärtsilä Marine; the biggest bankruptcy in the nordic countries until then
1993 The Troubles: A Provisional IRA bomb prematurely detonates in the Shankill area of Belfast, killing the bomber and nine civilians. Ulster loyalists retaliate a week later with the Greysteel massacre
1995 Yolanda Saldívar is found guilty of first-degree murder in the shooting death of popular Latin singer Selena. Three days later, Saldívar was sentenced to life in prison, eligible for parole in 2025
1998 Israeli–Palestinian conflict: Israeli Prime Minister Benjamin Netanyahu and Palestinian Chairman Yasser Arafat reach a "land for peace" agreement
1998 Swatch Internet Time, a measure of 1000 "beats" per day was inaugurated by the Swatch Group
2002 Moscow Theatre Siege begins: Chechen terrorists seize the House of Culture theater in Moscow and take approximately 700 theater-goers hostage
2004 A powerful earthquake and its aftershocks hit Niigata Prefecture, northern Japan, killing 35 people, injuring 2,200, and leaving 85,000 homeless or evacuated
2007 A powerful cold front in the Bay of Campeche causes the Usumacinta jackup rig to collide with Kab 101, leading to the death and drowning of 22 people during rescue operations after evacuation of the rig
2011 A powerful 7.2 magnitude earthquake strikes Van Province, Turkey, killing 582 people and injuring thousands