* 1282 – The people of Sicily rebel against the Angevin king Charles I, in what becomes known as the Sicilian Vespers.
* 1296 – Edward I sacks Berwick-upon-Tweed, during armed conflict between Scotland and England.
* 1814 – Napoleonic Wars: Sixth Coalition forces march into Paris.
* 1814 – Joachim Murat issues the Rimini Declaration which would later inspire Italian Unification.
* 1822 – The Florida Territory is created in the United States.
* 1842 – Anesthesia is used for the first time, in an operation by the American surgeon Dr. Crawford Long.
* 1844 – One of the most important battles of the Dominican War of Independence from Haiti takes place near the city of Santiago de los Caballeros.
* 1855 – Origins of the American Civil War: Bleeding Kansas – "Border Ruffians" from Missouri invade Kansas and force election of a pro-slavery legislature.
* 1856 – The Treaty of Paris is signed, ending the Crimean War.
* 1863 – Danish prince Wilhelm Georg is chosen as King George of Greece.
* 1867 – Alaska is purchased from Russia for $7.2 million, about 2 cent/acre ($4.19/km²), by United States Secretary of State William H. Seward.
* 1870 – Texas is readmitted to the Union following Reconstruction.
* 1885 – The Battle for Kushka triggers the Panjdeh Incident which nearly gives rise to war between the British Empire and Russian Empire.
* 1909 – The Queensboro Bridge opens, linking Manhattan and Queens.
* 1910 – The Mississippi Legislature founds The University of Southern Mississippi.
* 1912 – Sultan Abdelhafid signs the Treaty of Fez, making Morocco a French protectorate.
* 1918 – Outburst of bloody March Events in Baku and other locations of Baku Governorate.
* 1939 – The Heinkel He 100 fighter sets a world airspeed record of 463 mph.
* 1940 – Sino-Japanese War: Japan declares Nanking capital of a new Chinese puppet government, nominally controlled by Wang Ching-wei.
* 1944 – World War II: Allied bombers conduct their most severe bombing run on Sofia, Bulgaria.
* 1944 – Allied bombing raid on Nuremberg. Along the English eastern coast 795 aircraft are despatched, including 572 Lancasters, 214 Halifaxes and 9 Mosquitos. The bombers meet resistance at the coasts of Belgium and the Netherlands from German fighters. In total, 95 bombers are lost, making it the largest Bomber Command loss of World War II.
* 1945 – World War II: Soviet Union forces invade Austria and take Vienna; Polish and Soviet forces liberate Gdańsk.
* 1949 – A riot breaks out in Austurvöllur square in Reykjavík, when Iceland joins NATO.
* 1954 – The Yonge Street subway line opens in Toronto. It is the first subway in Canada.
* 1961 – The Single Convention on Narcotic Drugs is signed in New York City.
* 1965 – Vietnam War: A car bomb explodes in front of the US Embassy, Saigon, killing 22 and wounding 183 others.
* 1972 – Vietnam War: The Easter Offensive begins after North Vietnamese forces cross into the Demilitarized Zone (DMZ) of South Vietnam.
* 1976 – The first Land Day protests are held in Israel/Palestine.
* 1979 – Airey Neave, a British Member of Parliament, is killed by a car bomb as he exits the Palace of Westminster. The Irish National Liberation Army claims responsibility.
* 1981 – President Ronald Reagan is shot in the chest outside a Washington, D.C., hotel by John Hinckley, Jr.
* 1982 – Space Shuttle program: STS-3 Mission is completed with the landing of Columbia at White Sands Missile Range, New Mexico.
* 2006 – The United Kingdom Terrorism Act 2006 becomes a law.
* 2009 – Twelve gunmen attack the Manawan Police Academy in Lahore, Pakistan.