2015: At least 46 people are killed as a result of floods caused by a tornado in Texas and Oklahoma.
2014: Seven people, including the perpetrator, are killed and another 14 injured in a killing spree near the campus of University of California, Santa Barbara.
1995: The first version of the Java programming language is released.
1992: Italy's most prominent anti-mafia judge Giovanni Falcone, his wife and three body guards are killed by the Corleonesi clan with a half-ton bomb near Capaci, Sicily. His friend and colleague Paolo Borsellino will be assassinated less than two months later, making 1992 a turning point in the history of Italian Mafia prosecutions.
1945: World War II: The Flensburg Government under Reichspräsident Karl Dönitz is dissolved when its members are captured and arrested by British forces.
1939: The U.S. Navy submarine USS Squalus sinks off the coast of New Hampshire during a test dive, causing the death of 24 sailors and two civilian technicians. The remaining 32 sailors and one civilian naval architect are rescued the following day.
1934: The Auto-Lite strike culminates in the "Battle of Toledo", a five-day melée between 1,300 troops of the Ohio National Guard and 6,000 picketers.
1932: In Brazil, four students are shot and killed during a manifestation against the Brazilian dictator Getúlio Vargas, which resulted in the outbreak of the Constitutionalist Revolution several weeks later.
1915: World War I: Italy joins the Allies, fulfilling its part of the Treaty of London.
1846: Mexican-American War: President Mariano Paredes of Mexico unofficially declares war on the United States.
1844: Declaration of the Báb the evening before the 23rd: A merchant of Shiraz announces that he is a Prophet and founds a religious movement that would later be brutally crushed by the Persian government. He is considered to be a forerunner of the Bahá'í Faith; Bahá'ís celebrate the day as a holy day.
844: Battle of Clavijo: The Apostle Saint James the Greater is said to have miraculously appeared to a force of outnumbered Asturians and aided them against the forces of the Emir of Cordoba.