Today in History : March 31

• 307 – After divorcing his wife Minervina, Constantine marries Fausta, the daughter of the retired Roman Emperor Maximian.
• 627 – Battle of the Trench: Muhammad successfully withstands a siege for 27 days at Medina (Saudi Arabia) by Meccan forces under Abu Sufyan.
• 1146 – Bernard of Clairvaux preaches his famous sermon in a field at Vézelay, urging the necessity of a Second Crusade. Louis VII is present, and joins the Crusade.
• 1492 – Queen Isabella of Castille issues the Alhambra decree, ordering her 150,000 Jewish and Muslim subjects to convert to Christianity or face expulsion.
• 1717 – A sermon on "The Nature of the Kingdom of Christ" by Benjamin Hoadly, the Bishop of Bangor, provokes the Bangorian Controversy.
• 1774 – American Revolutionary War: The Kingdom of Great Britain orders the port of Boston, Massachusetts closed pursuant to the Boston Port Act.
• 1822 – The massacre of the population of the Greek island of Chios by soldiers of the Ottoman Empire following an attempted rebellion, depicted by the French artist Eugène Delacroix.
• 1854 – Commodore Matthew Perry signs the Treaty of Kanagawa with the Japanese government, opening the ports of Shimoda and Hakodate toAmerican trade.
• 1866 – The Spanish Navy bombs the harbor of Valparaíso, Chile.
• 1877 – The family with samurai antecedents that responded to the Saigō army in Ōita Nakatsu, rebels.
• 1885 – The United Kingdom establishes a protectorate over Bechuanaland.
• 1889 – The Eiffel Tower is officially opened.
• 1899 – Malolos, capital of the First Philippine Republic, was captured by American forces.
• 1901 – 1901 Black Sea earthquake
• 1903 – Richard Pearse allegedly makes a powered flight in an early aircraft.
• 1906 – The Intercollegiate Athletic Association of the United States (later the National Collegiate Athletic Association) is established to set rules for college sports in the United States.
• 1909 – Serbia accepts Austrian control over Bosnia and Herzegovina.
• 1909 – Construction of the ill fated RMS Titanic begins.
• 1910 – Six North Staffordshire Pottery towns federate to form modern Stoke-on-Trent.
• 1913 – The Vienna Concert Society rioted during a performance of mordernist music by Arnold Schoenberg, Alban Berg, Alexander von Zemlinsky, and Anton von Webern, causing a premature end to the concert due to violence. This concert became known as the Skandalkonzert.
• 1917 – The United States takes possession of the Danish West Indies after paying $25 million to Denmark, and renames the territory the United States Virgin Islands.
• 1918 – Massacre of ethnic Azerbaijanis is committed by allied armed groups of Armenian Revolutionary Federation and Bolsheviks. Nearly 12,000 Azerbaijani Muslims are killed.
• 1918 – Daylight saving time goes into effect in the United States for the first time.
• 1921 – The Royal Australian Air Force is formed.
• 1930 – The Motion Pictures Production Code is instituted, imposing strict guidelines on the treatment of sex, crime, religion and violence in film, in the U.S., for the next thirty eight years.
• 1931 – An earthquake destroys Managua, Nicaragua, killing 2,000.
• 1931 – TWA Flight 599 crashes near Bazaar, Kansas, killing eight, including University of Notre Dame head football coach Knute Rockne.
• 1933 – The Civilian Conservation Corps is established with the mission of relieving rampant unemployment in the United States.
• 1942 – World War II: Japanese forces invade Christmas Island, then a British possession.
• 1945 – World War II: a defecting German pilot delivers a Messerschmitt Me 262A-1, the world's first operational jet-powered fighter aircraft, to the Americans, the first to fall into Allied hands.
• 1949 – The Dominion of Newfoundland joins the Canadian Confederation and becomes the 10th Province of Canada.
• 1951 – Remington Rand delivers the first UNIVAC I computer to the United States Census Bureau.
• 1957 – Elections to the Territorial Assembly of the French colony Upper Volta are held. After the elections PDU and MDV form a government.
• 1958 – In the Canadian federal election, the Progressive Conservatives, led by John Diefenbaker, win the largest percentage of seats in Canadian history, with 208 seats of 265.
• 1959 – The 14th Dalai Lama, Tenzin Gyatso, crosses the border into India and is granted political asylum.
• 1964 – A coup d'état in Brazil establishes a military government, under the aegis of general Castello Branco.
• 1965 – An Iberia Airlines Convair 440 crashes into the sea on approach to Tangier, killing 47 of 51 occupants.
• 1966 – The Soviet Union launches Luna 10 which later becomes the first space probe to enter orbit around the Moon.
• 1970 – Explorer 1 re-enters the Earth's atmosphere after 12 years in orbit.
• 1970 – Nine terrorists from the Japanese Red Army hijack Japan Airlines Flight 351 at Tokyo International Airport, wielding samurai swords and carrying a bomb.
• 1979 – The last British soldier leaves the Maltese Islands. Malta declares its Freedom Day (Jum il-Helsien).
• 1980 – The Chicago, Rock Island and Pacific railroad operates its final train after being ordered to liquidate its assets because of bankruptcy and debts owed to creditors.
• 1985 – The first WrestleMania, the biggest wrestling event from the WWE (then the WWF), takes place in Madison Square Garden in New York.
• 1986 – A Mexicana Boeing 727 en route to Puerto Vallarta erupts in flames and crashes in the mountains northwest of Mexico City, killing 167.
• 1986 – Six metropolitan county councils are abolished in England.
• 1990 – Approximately 200,000 protestors take to the streets of London to protest against the newly introduced Poll Tax.
• 1991 – Georgian independence referendum, 1991: Nearly 99 percent of the voters support the country's independence from the Soviet Union.
• 1992 – The USS Missouri, the last active United States Navy battleship, is decommissioned in Long Beach, California.
• 1994 – The journal Nature reports the finding in Ethiopia of the first complete Australopithecus afarensis skull.
• 1995 – TAROM Flight 371 crashed, killing all of the ten crew and 50 passengers on board.
• 1995 – Selena, an American singer, was murdered by her friend and employee of her boutiques Yolanda Saldívar who was embezzling money from the establishments. The event was named "Black Friday" by Hispanics.
• 2004 – Iraq War in Anbar Province - In Fallujah, Iraq, four American private military contractors working for Blackwater USA, are killed after being ambushed.