| 20581 | February 22 | Holiday and observance | Christian feast day:BaradatesEric Liddell (Episcopal Church (USA))Feast of the Chair of Saint Peter (Roman Catholic Church)Margaret of CortonaFebruary 22 (Eastern Orthodox liturgics) |
| 20582 | February 22 | Holiday and observance | Independence Day (Saint Lucia), celebrates the independence of Saint Lucia from the United Kingdom in 1979. |
| 20583 | February 23 | Event | 303 – Roman emperor Diocletian orders the destruction of the Christian church in Nicomedia, beginning eight years of Diocletianic Persecution. |
| 20584 | February 23 | Event | 532 – Byzantine emperor Justinian I orders the building of a new Orthodox Christian basilica in Constantinople – the Hagia Sophia. |
| 20585 | February 23 | Event | 1455 – Traditional date for the publication of the Gutenberg Bible, the first Western book printed with movable type. |
| 20586 | February 23 | Event | 1554 – Mapuche forces, under the leadership of Lautaro, score a victory over the Spanish at the Battle of Marihueñu in Chile. |
| 20587 | February 23 | Event | 1739 – Richard Palmer is identified at York Castle, by his former schoolteacher, as the outlaw Dick Turpin. |
| 20588 | February 23 | Event | 1778 – American Revolutionary War: Baron von Steuben arrives at Valley Forge, Pennsylvania to help to train the Continental Army. |
| 20589 | February 23 | Event | 1820 – Cato Street Conspiracy: A plot to murder all the British cabinet ministers is exposed. |
| 20590 | February 23 | Event | 1821 – Alexander Ypsilantis starts the Greek War of Independence in Iași, Wallachia (now part of Romania). |
| 20591 | February 23 | Event | 1836 – Texas Revolution: The Battle of the Alamo begins in San Antonio, Texas. |
| 20592 | February 23 | Event | 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. |
| 20593 | February 23 | Event | 1854 – The official independence of the Orange Free State is declared. |
| 20594 | February 23 | Event | 1861 – President-elect Abraham Lincoln arrives secretly in Washington, D.C., after the thwarting of an alleged assassination plot in Baltimore, Maryland. |
| 20595 | February 23 | Event | 1870 – Reconstruction Era: Post-U.S. Civil War military control of Mississippi ends and it is readmitted to the Union. |
| 20596 | February 23 | Event | 1883 – Alabama becomes the first U.S. state to enact an anti-trust law. |
| 20597 | February 23 | Event | 1885 – Sino-French War: French Army gains an important victory in the Battle of Đồng Đăng in the Tonkin region of Vietnam. |
| 20598 | February 23 | Event | 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. |
| 20599 | February 23 | Event | 1887 – The French Riviera is hit by a large earthquake, killing around 2,000. |
| 20600 | February 23 | Event | 1896 – The Tootsie Roll is invented. |
| 20601 | February 23 | Event | 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. |
| 20602 | February 23 | Event | 1900 – Second Boer War: Boers and British troops fight in the Battle of Hart's Hill. |
| 20603 | February 23 | Event | 1903 – Cuba leases Guantánamo Bay to the United States "in perpetuity". |
| 20604 | February 23 | Event | 1905 – Chicago attorney Paul Harris and three other businessmen meet for lunch to form the Rotary Club, the world's first service club. |
| 20605 | February 23 | Event | 1909 – The AEA Silver Dart makes the first powered flight in Canada and the British Empire. |
| 20606 | February 23 | Event | 1917 – First demonstrations in Saint Petersburg, Russia. The beginning of the February Revolution. |
| 20607 | February 23 | Event | 1918 – Last monarch of Grand Duke of Mecklenburg-Strelitz commits suicide. |
| 20608 | February 23 | Event | 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. |
| 20609 | February 23 | Event | 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. |
| 20610 | February 23 | Event | 1934 – Leopold III becomes King of Belgium. |