23 February Events

February 23 is the 54th day of the year in the Gregorian calendar. There are 311 days remaining until the end of the year (312 in leap years). This date is slightly more likely to fall on a Tuesday, Thursday or Saturday (58 in 400 years each) than on Sunday or Monday (57), and slightly less likely to occur on a Wednesday or Friday (56).
Events
303 – Roman emperor Diocletian orders the destruction of the Christian church in Nicomedia, beginning eight years of Diocletianic Persecution.
532 – Byzantine emperor Justinian I orders the building of a new Orthodox Christian basilica in Constantinople – the Hagia Sophia.
1455 – Traditional date for the publication of the Gutenberg Bible, the first Western book printed with movable type.
1554 – Mapuche forces, under the leadership of Lautaro, score a victory over the Spanish at the Battle of Marihueñu in Chile.
1739 – At York Castle, the outlaw Dick Turpin is identified by his former schoolteacher. Turpin had been using the name Richard Palmer.
1778 – American Revolutionary War: Baron von Steuben arrives at Valley Forge, Pennsylvania to help to train the Continental Army.
1820 – Cato Street Conspiracy: A plot to murder all the British cabinet ministers is exposed.
1836 – Texas Revolution: The Siege of the Alamo (prelude to the Battle of the Alamo) begins in San Antonio, Texas.
1847 – Mexican–American War: Battle of Buena Vista: In Mexico, American troops under future president General Zachary Taylor defeat Mexican General Antonio López de Santa Anna.
1854 – The official independence of the Orange Free State is declared.
1861 – President-elect Abraham Lincoln arrives secretly in Washington, D.C., after the thwarting of an alleged assassination plot in Baltimore, Maryland.
1870 – Reconstruction Era: Post-U.S. Civil War military control of Mississippi ends and it is readmitted to the Union.
1883 – Alabama becomes the first U.S. state to enact an anti-trust law.
1885 – Sino-French War: French Army gains an important victory in the Battle of Đồng Đăng in the Tonkin region of Vietnam.
1886 – Charles Martin Hall produced the first samples of man-made aluminum, after several years of intensive work. He was assisted in this project by his older sister, Julia Brainerd Hall.
1887 – The French Riviera is hit by a large earthquake, killing around 2,000.
1898 – Émile Zola is imprisoned in France after writing "J'accuse", a letter accusing the French government of antisemitism and wrongfully imprisoning Captain Alfred Dreyfus.
1900 – Second Boer War: During the Battle of the Tugela Heights, the first British attempt to take Hart's Hill fails.
1903 – Cuba leases Guantánamo Bay to the United States "in perpetuity".
1905 – Chicago attorney Paul Harris and three other businessmen meet for lunch to form the Rotary Club, the world's first service club.
1909 – The AEA Silver Dart makes the first powered flight in Canada and the British Empire.
1917 – First demonstrations in Saint Petersburg, Russia. The beginning of the February Revolution (March 8th in the Gregorian calendar).
1927 – U.S. President Calvin Coolidge signs a bill by Congress establishing the Federal Radio Commission (later replaced by the Federal Communications Commission) which was to regulate the use of radio frequencies in the United States.
1927 – German theoretical physicist Werner Heisenberg writes a letter to fellow physicist Wolfgang Pauli, in which he describes his uncertainty principle for the first time.
1934 – Leopold III becomes King of Belgium.
1941 – Plutonium is first produced and isolated by Dr. Glenn T. Seaborg.
1942 – World War II: Japanese submarines fire artillery shells at the coastline near Santa Barbara, California.
1943 – A fire breaks out at Saint Joseph's Orphanage, County Cavan, Ireland, killing 35 children and one adult.
1943 – Greek Resistance: The United Panhellenic Organization of Youth is founded is Greece.
1944 – The Soviet Union begins the forced deportation of the Chechen and Ingush people from the North Caucasus to Central Asia.
1945 – World War II: During the Battle of Iwo Jima, a group of United States Marines and a U.S. Navy hospital corpsman reach the top of Mount Suribachi on the island and are photographed raising the American flag.
1945 – World War II: The 11th Airborne Division, with Filipino guerrillas, free the captives of the Los Baños internment camp.
1945 – World War II: The capital of the Philippines, Manila, is liberated by combined Filipino and American forces.
1945 – World War II: Capitulation of German garrison in Poznań. The city is liberated by Soviet and Polish forces.
1945 – World War II: The German town of Pforzheim is annihilated in a raid by 379 British bombers.
1954 – The first mass inoculation of children against polio with the Salk vaccine begins in Pittsburgh.
1966 – In Syria, Ba'ath Party member Salah Jadid leads an intra-party military coup that replaces the previous government of General Amin al-Hafiz, also a Baathist.
1974 – The Symbionese Liberation Army demands $4 million more to release kidnap victim Patty Hearst.
1980 – Iran hostage crisis: Supreme Leader Ayatollah Ruhollah Khomeini states that Iran's parliament will decide the fate of the American embassy hostages.
1981 – In Spain, Antonio Tejero attempts a coup d'état by capturing the Spanish Congress of Deputies.
1983 – The United States Environmental Protection Agency announces its intent to buy out and evacuate the dioxin-contaminated community of Times Beach, Missouri.
1987 – Supernova 1987a is seen in the Large Magellanic Cloud.
1991 – Gulf War: Ground troops cross the Saudi Arabian border and enter Iraq, thus beginning the ground phase of the war.
1991 – In Thailand, General Sunthorn Kongsompong leads a bloodless coup d'état, deposing Prime Minister Chatichai Choonhavan.
1998 – In the United States, tornadoes in central Florida destroy or damage 2,600 structures and kill 42 people.
1999 – Kurdish rebel leader Abdullah Öcalan is charged with treason in Ankara, Turkey.
2007 – A train derails on an evening express service near Grayrigg, Cumbria, England, killing one person and injuring 88. This results in hundreds of points being checked over the UK after a few similar accidents.
2008 – A United States Air Force B-2 Spirit bomber crashes on Guam, marking the first operational loss of a B-2.
2010 – Unknown criminals pour more than 2.5 million liters of diesel oil and other hydrocarbons into the river Lambro, in northern Italy, sparking an environmental disaster.
2012 – A series of attacks across Iraq leave at least 83 killed and more than 250 injured.
Holidays and observances

Christian feast day:
Polycarp of Smyrna
Serenus the Gardener
February 23 (Eastern Orthodox liturgics)
Mashramani-Republic Day (Guyana)
Meteņi (Latvia)
National Day (Brunei)
Red Army Day or Day of Soviet Army and Navy in the former Soviet Union, also held in various former Soviet republics:
Defender of the Fatherland Day (Russia)
Defender of the Fatherland and Armed Forces day (Belarus)
Terminalia held in honor of Terminus (Ancient Rome)

Source: Wikipedia