* 421 – Venice is founded at twelve o'clock noon, according to legend.
* 1199 – Richard I is wounded by a crossbow bolt while fighting France, leading to his death on April 6.
* 1306 – Robert the Bruce becomes King of Scotland.
* 1409 – The Council of Pisa opens.
* 1584 – Sir Walter Raleigh is granted a patent to colonize Virginia.
* 1634 – The first settlers arrive in Maryland.
* 1655 – Saturn's largest moon, Titan, is discovered by Christiaan Huygens.
* 1802 – The Treaty of Amiens is signed as a "Definitive Treaty of Peace" between France and the United Kingdom.
* 1807 – The Slave Trade Act becomes law, abolishing the slave trade in the British Empire.
* 1807 – The Swansea and Mumbles Railway, then known as the Oystermouth Railway, becomes the first passenger carrying railway in the world.
* 1811 – Percy Bysshe Shelley is expelled from the University of Oxford for publishing the pamphlet The Necessity of Atheism.
* 1821 – (Julian Calendar) Traditional date of the start of the Greek War of Independence. The war had actually began since 23 February 1821. The date was chosen in the early years of the Greek state so that it falls on the day of the Annunciation of the Blessed Virgin Mary, strengthening the ties between the Greek Orthodox Church and the newly-found state.
* 1865 – American Civil War: In Virginia, Confederate forces temporarily capture Fort Stedman from the Union.
* 1894 – Coxey's Army, the first significant American protest march, departs Massillon, Ohio for Washington D.C.
* 1911 – In New York City, the Triangle Shirtwaist Factory fire kills 146 garment workers.
* 1917 – The Georgian Orthodox Church restores its autocephaly abolished by Imperial Russia in 1811.
* 1918 – The Belarusian People's Republic is established.
* 1924 – On the anniversary of Greek Independence, Alexandros Papanastasiou proclaims the Second Hellenic Republic.
* 1931 – The Scottsboro Boys are arrested in Alabama and charged with rape.
* 1941 – The Kingdom of Yugoslavia joins the Axis powers with the signing of the Tripartite Pact.
* 1943 – Start of the American amphibious landings in the Philippines a turning point in the Pacific War.
* 1947 – An explosion in a coal mine in Centralia, Illinois kills 111.
* 1948 – The first successful tornado forecast predicts that a tornado will strike Tinker Air Force Base, Oklahoma.
* 1949 – The extensive deportation campaign known as March deportation is conducted in Estonia, Latvia and Lithuania to force collectivisation by way of terror. The Soviet authorities deport more than 92,000 people from the Baltics to remote areas of the Soviet Union.
* 1957 – United States Customs seizes copies of Allen Ginsberg's poem "Howl" on the grounds of obscenity.
* 1957 – The European Economic Community is established (West Germany, France, Italy, Belgium, Netherlands, Luxembourg).
* 1958 – Canada's Avro Arrow makes its first flight.
* 1965 – Civil rights activists led by Martin Luther King, Jr. successfully complete their 4-day 50-mile march from Selma to the capitol in Montgomery, Alabama.
* 1969 – During their honeymoon, John Lennon and Yoko Ono hold their first Bed-In for Peace at the Amsterdam Hilton Hotel (until March 31).
* 1971 – Bangladesh Liberation War: Beginning of Operation Searchlight by the Pakistani Armed Forces against East Pakistani civilians.
* 1971 – The Army of the Republic of Vietnam abandon an attempt to cut off the Ho Chi Minh trail in Laos.
* 1975 – Faisal of Saudi Arabia is shot and killed by a mentally ill nephew.
* 1979 – The first fully functional space shuttle orbiter, Columbia, is delivered to the John F. Kennedy Space Center to be prepared for its first launch.
* 1988 – The Candle demonstration in Bratislava is the first mass demonstration of the 1980s against the communist regime in Czechoslovakia.
* 1990 – The Happy Land fire was an arson fire that kills 87 people trapped inside an illegal nightclub in the New York City borough of The Bronx.
* 1992 – Cosmonaut Sergei Krikalev returns to Earth after a 10-month stay aboard the Mir space station.
* 1995 – WikiWikiWeb, the world's first wiki, and part of the Portland Pattern Repository, is made public by Ward Cunningham.
* 1996 – An 81-day-long standoff between the anti-government group Montana Freemen and law enforcement near Jordan, Montana, begins.
* 1996 – The European Union's Veterinarian Committee bans the export of British beef and its by-products as a result of mad cow disease (Bovine spongiform encephalopathy).
* 2006 – Capitol Hill massacre: A gunman kills six people before taking his own life at a party in Seattle's Capitol Hill neighborhood.
* 2006 – Protesters demanding a new election in Belarus, following the rigged Belarusian presidential election, 2006, clash with riot police. Opposition leader Aleksander Kozulin is among several protesters arrested.