# 1077 – Walk to Canossa: The excommunication of Henry IV, Holy Roman Emperor is lifted.
# 1521 – The Diet of Worms begins, lasting until May 25.
# 1547 – Henry VIII dies. His nine year old son, Edward VI becomes King, and the first Protestant ruler of England.
# 1573 – Articles of the Warsaw Confederation are signed, sanctioning freedom of religion in Poland.
# 1624 – Sir Thomas Warner founds the first British colony in the Caribbean, on the island of Saint Kitts.
# 1724 – The Russian Academy of Sciences is founded in St. Petersburg by Peter the Great, and implemented by Senate decree. It is called the St. Petersburg Academy of Sciences until 1917.
# 1754 – Horace Walpole coins the word serendipity in a letter to Horace Mann.
# 1760 – Pownal, Vermont is created by Benning Wentworth as one of the New Hampshire Grants.
# 1813 – Pride and Prejudice is first published in the United Kingdom.
# 1820 – A Russian expedition led by Fabian Gottlieb von Bellingshausen and Mikhail Petrovich Lazarev discovers the Antarctic continent approaching the Antarctic coast.
# 1821 – Alexander Island is first discovered by Fabian Gottlieb von Bellingshausen.
# 1846 – The Battle of Aliwal, India, is won by British troops commanded by Sir Harry Smith.
# 1851 – Northwestern University becomes the first chartered university in Illinois.
# 1855 – The first locomotive runs from the Atlantic Ocean to the Pacific Ocean on the Panama Railway.
# 1871 – Franco-Prussian War: the Siege of Paris ends in French defeat and an armistice.
# 1878 – Yale Daily 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, 15 inches (38 cm) wide and 8 inches (20 cm) thick.
# 1896 – Walter Arnold of East Peckham, Kent became the first person to be convicted of speeding. He is fined 1 shilling, plus costs, for speeding at 8 mph (13 km/h), thus exceeding the contemporary speed limit of 2 mph (3.2 km/h).
# 1902 – The Carnegie Institution of Washington is founded in Washington, D.C. with a $10 million gift from Andrew Carnegie.
# 1908 – Members of the Portuguese Republican Party fail in their attempted coup d'état against the administrative dictatorship of Prime Minister João Franco.
# 1909 – United States troops leave Cuba with the exception of Guantanamo Bay Naval Base after being there since the Spanish-American War.
# 1915 – An act of the U.S. Congress creates the United States Coast Guard.
# 1917 – Municipally owned streetcars take to the streets of San Francisco, California.
# 1918 – Finnish Civil War: Rebels seized control of the capital, Helsinki, and members of the Senate of Finland go underground.
# 1922 – Knickerbocker Storm, Washington D.C.'s biggest snowfall, causes the city's greatest loss of life when the roof of the Knickerbocker Theatre collapses.
# 1932 – Japanese forces attack Shanghai.
# 1933 – The name Pakistan is coined by Choudhary Rehmat Ali Khan and is accepted by the Indian Muslims who then thereby adopted it further for the Pakistan Movement seeking independence.
# 1934 – The first ski tow in the United States begins operation in Vermont.
# 1935 – Iceland becomes the first Western country to legalize therapeutic abortion.
# 1938 – The World Land Speed Record on a public road is broken by driver Rudolf Caracciola in the Mercedes-Benz W195 at a speed of 432.7 kilometres per hour (268.9 mph).
# 1941 – French-Thai War: Final air battle of the conflict. Japanese-mediated armistice goes into effect later in the day.
# 1945 – World War II: Supplies begin to reach the Republic of China over the newly reopened Burma Road.
# 1956 – Elvis Presley made his first US TV appearance
# 1958 – The Lego company patents the design of its Lego bricks, still compatible with bricks produced today.
# 1958 – The last episode of the British radio comedy programme Goon Show was broadcast.
# 1964 – An unarmed USAF T-39 Sabreliner on a training mission is shot down over Erfurt, East Germany, by a Soviet MiG-19.
# 1965 – The current design of the Flag of Canada is chosen by an act of Parliament.
# 1977 – The first day of the Great Lakes Blizzard of 1977, which severely affects and cripples much of Upstate New York, but Buffalo, NY, Syracuse, NY, Watertown, NY, and surrounding areas are most affected, each area accumulating close to 10 feet (3.0 m) of snow on this one day.
# 1980 – USCGC Blackthorn collides with the tanker Capricorn while leaving Tampa Florida and capsizes killing 23 Coast Guard crewmembers.
# 1981 – Ronald Reagan lifts remaining domestic petroleum price and allocation controls in the United States helping to end the 1979 energy crisis and begin the 1980s oil glut.
# 1982 – US Army general James L. Dozier is rescued by Italian anti-terrorism forces from captivity by the Red Brigades.
# 1984 – Tropical Storm Domoina makes landfall in southern Mozambique, eventually causing 214 deaths and some of the most severe flooding so far recorded in the region.
# 1985 – Supergroup USA for Africa (United Support of Artists for Africa) records the hit single We Are the World, to help raise funds for Ethiopian famine relief.
# 1986 – Space Shuttle program: STS-51-L mission – Space Shuttle Challenger breaks apart after liftoff killing all seven astronauts on board.
# 1988 – The last episode of the British TV series Yes, Prime Minister, entitled The Tangled Web, was broadcast.
# 2002 – TAME Flight 120, a Boeing 727-100 crashes in the Andes mountains in southern Colombia killing 92.
# 2006 – The roof of one of the buildings at the Katowice International Fair in Chorzów / Katowice, Poland, collapses due to the weight of snow, killing 65 and injuring more than 170 others.
# 2010 – Five murderers of President Sheikh Mujibur Rahman of Bangladesh: Lieutenant Colonel Syed Faruq Rahman, Lieutenant Colonel Sultan Shahriar Rashid Khan, Major AKM Mohiuddin Ahmed, Major Bazlul Huda and Lieutenant Colonel Mohiuddin Ahmed are hanged.
# 2011 – Hundreds of thousands of protesters filled up the Egyptian's streets in demonstrations referred to as "Friday of Anger" against the Mubarak regime.