| | 1077 - Walk to Canossa: The excommunication of Henry IV, Holy Roman Emperor is lifted. |
| | 1521 - Diet of Worms begins, lasting until May 25. |
| | 1547 - Edward VI becomes King, and the first Protestant ruler of England. |
| | 1573 - Articles of Warsaw Confederation are signed, sanctioning freedom of religion in Poland. |
| | 1754 - Horace Walpole, in a letter to Horace Mann, coins the word serendipity. |
| | 1760 - Pownal, Vermont created by Benning Wentworth as one of the New Hampshire Grants. |
| | 1788 - The first penal colony is founded at Botany Bay, Australia. |
| | 1813 - Pride and Prejudice is first published in the United Kingdom. |
| | 1820 - Russian expedition led by Fabian Gottlieb von Bellingshausen and Mikhail Petrovich Lazarev discovered the Antarctic continent approaching the Antarctic coast. |
| | 1846 - Battle of Aliwal, India won by British troops commanded by Sir Harry Smith. |
| | 1855 - The first locomotive runs from the Atlantic to the Pacific on the Panama Railway. |
| | 1871 - Franco-Prussian War: France surrenders, ending the war. |
| | 1878 - The Yale News becomes the first daily, college newspaper in the United States. |
| | 1887 - In a snowstorm at Fort Keogh, Montana, the world's largest snowflakes are reported, being 15 inches (38 cm) wide and 8 inches (20 cm) thick. |
| | 1902 - The Carnegie Institution is founded in Washington, DC with a $10 million gift from Andrew Carnegie. |
| | 1909 - United States troops leave Cuba after being there since the Spanish-American War. |
| | 1915 - An act of the U.S. Congress creates the United States Coast Guard. |
| | 1916 - Louis D. Brandeis becomes the first Jew appointed to the United States Supreme Court. |
| | 1917 - United States ends search for Pancho Villa. |
| | 1917 - Municipally owned streetcars take to the streets of San Francisco. |
| | 1918 - Finnish Civil War: Rebels seized control of the capital, Helsinki, and members of the Senate of Finland go underground. |
| | 1921 - A symbolic Tomb of the Unknown Soldier is installed beneath the Arc de Triomphe in Paris to honour the unknown dead of World War I. |
| | 1932 - Japan occupies Shanghai. |
| | 1933 - The name Pakistan is coined by Choudhary Rehmat Ali Khan and by a group of Cambridge University Students and is accepted by the Indian Muslims who then thereby adopted it further for the Pakistan Movement of the formal Indian Independence Act 1947 during World War II |
| | 1935 - Iceland becomes the first country to legalize abortion. |
| | 1938 - The first ski tow in America begins operation in Vermont. |
| | 1938 - The World Land Speed Record on a public road is broken by driver Rudolf Caracciola in the Mercedes-Benz W195. |
| | 1945 - World War II: Supplies begin to reach the Republic of China over the newly reopened Burma Road. |
| | 1946 - Bluenose, Canada's greatest sailing ship, founders on a Haitian reef. |
| | 1952 - Derek Bentley hanged for murder. |
| | 1958 - Charles Starkweather and Caril Ann Fugate begin their murder spree with the killings of her parents and infant sister. |
| | 1982 - US Army general James L. Dozier is rescued by Italian anti-terrorism forces after 42 days of captivity under the Red Brigades. |
| | Explosion of the Space Shuttle Challenger.1986 - Space Shuttle program: STS-51-L mission (Space Shuttle Challenger disaster) - Space Shuttle Challenger breaks apart 73 seconds after liftoff killing all seven astronauts onboard, including Christa McAuliffe, who was supposed to be the first teacher in space. Failure blamed on leaking Space Shuttle Solid Rocket Booster. |
| | 1994 - The first trial of accused murderer Lyle Menendez ends in a mistrial. He and his brother Erik are later found guilty and sentenced to life in prison without parole. |
| | 1998 - Gunmen hold at least 400 children and teachers hostage for several hours at an elementary school in Manila, Philippines. |
| | 2002 - TAME Flight 120, a Boeing 727-100 crashes in the Andes mountains in southern Colombia killing 92. |
| | 2004 - Lord Hutton publishes his report into the death of UN weapons inspector Dr David Kelly. |