March 25 is the 84th day of the year (85th in leap years) in the Gregorian calendar. There are 281 days remaining until the end of the year.
- 708 – Pope Constantine succeeds Pope Sisinnius as the 88th pope.
- 717 – Theodosius III resigns the throne to the Byzantine Empire to enter the clergy.
- 919 – Romanos Lekapenos seizes the Boukoleon Palace in Constantinople and becomes regent of the Byzantine emperor Constantine VII.
- 1000 – Fatimid caliph al-Hakim bi-Amr Allah assassinates the eunuch chief minister Barjawan and assumes control of the government.
- 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 Scots (Scotland).
- 1409 – The Council of Pisa opens.
- 1555 – The city of Valencia is founded in present-day Venezuela.
- 1576 – Jerome Savage takes out a sub-lease to start the Newington Butts Theatre outside London.
- 1584 – Sir Walter Raleigh is granted a patent to colonize Virginia.
- 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 – Traditional date of the start of the Greek War of Independence. The war had actually begun on 23 February 1821 (Julian calendar).
- 1845 – New Zealand Legislative Council pass the first Militia Act constituting the New Zealand Army.[1]
- 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.
- 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 – More than 92,000 kulaks are suddenly deported from the Baltic states to Siberia.
- 1957 – United States Customs seizes copies of Allen Ginsberg's poem "Howl" on obscenity grounds.
- 1957 – The European Economic Community is established with West Germany, France, Italy, Belgium, Netherlands and Luxembourg as the first members.
- 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 – 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.
- 1995 – WikiWikiWeb, the world's first wiki, and part of the Portland Pattern Repository, is made public by Ward Cunningham.
- 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.
