May 24 is the 144th day of the year (145th in leap years) in the Gregorian calendar; 221 days remain until the end of the year.
919 – The nobles of Franconia and Saxony elect Henry the Fowler at the Imperial Diet in Fritzlar as king of the East Frankish Kingdom.
1218 – The Fifth Crusade leaves Acre for Egypt.
1276 – Magnus Ladulås is crowned King of Sweden in Uppsala Cathedral.
1487 – The ten-year-old Lambert Simnel is crowned in Christ Church Cathedral, Dublin, Ireland, with the name of Edward VI in a bid to threaten King Henry VII‘s reign.

1543 – Nicolaus Copernicus, Polish mathematician and astronomer (b. 1473) dies. He was a Renaissance polymath who formulated a model of the universe that placed the Sun rather than Earth at its center. Copernicus likely developed his model independently of Aristarchus of Samos, an ancient Greek astronomer who had formulated such a model some eighteen centuries earlier.
1567 – Erik XIV of Sweden and his guards murder five incarcerated Swedish nobles.
1595 – Nomenclator of Leiden University Library appears, the first printed catalog of an institutional library.
1607 – Jamestown, the first permanent English colony in North America, is founded.[1]
1621 – The Protestant Union is formally dissolved.
1626 – Peter Minuit buys Manhattan.
1667 – The French Royal Army crosses the border into the Spanish Netherlands, starting the War of Devolution opposing France to the Spanish Empire and the Triple Alliance.
1683 – The Ashmolean Museum in Oxford, England, opens as the world’s first university museum.
1689 – The English Parliament passes the Act of Toleration protecting dissenting Protestants but excluding Roman Catholics.
1738 – John Wesley is converted, essentially launching the Methodist movement; the day is celebrated annually by Methodists as Aldersgate Day and a church service is generally held on the preceding Sunday.
1798 – The Irish Rebellion of 1798 led by the United Irishmen against British rule begins.
1813 – South American independence leader Simón Bolívar enters Mérida, leading the invasion of Venezuela, and is proclaimed El Libertador (“The Liberator”).
1822 – Battle of Pichincha: Antonio José de Sucre secures the independence of the Presidency of Quito.
1832 – The First Kingdom of Greece is declared in the London Conference.
1844 – Samuel Morse sends the message “What hath God wrought” (a biblical quotation, Numbers 23:23) from a committee room in the United States Capitol to his assistant, Alfred Vail, in Baltimore, Maryland, to inaugurate a commercial telegraph line between Baltimore and Washington D.C.[2]
1856 – John Brown and his men kill five slavery supporters at Pottawatomie Creek, Kansas.

1861 – American Civil War: Union troops occupy Alexandria, Virginia, with Colonel Elmer E. Ellsworth becoming the first Union officer to be killed during the war. was a United States Army officer and law clerk who was the first conspicuous casualty and the first Union officer to die in the American Civil War. He was killed while removing a Confederate flag from the roof of the Marshall House inn in Alexandria, Virginia
1873 – Patrick Francis Healy becomes the first black president of a predominantly white university in the United States.
1883 – The Brooklyn Bridge in New York City is opened to traffic after 14 years of construction.
1900 – Second Boer War: The United Kingdom annexes the Orange Free State.
1915 – World War I: Italy declares war on Austria-Hungary, joining the conflict on the side of the Allies.
1930 – Amy Johnson lands in Darwin, Northern Territory, becoming the first woman to fly solo from England to Australia (she left on May 5 for the 11,000 mile flight).
1935 – The first night game in Major League Baseball history is played in Cincinnati, Ohio, with the Cincinnati Reds beating the Philadelphia Phillies 2–1 at Crosley Field.
1940 – Igor Sikorsky performs the first successful single-rotor helicopter flight.
1940 – Acting on the orders of Soviet leader Joseph Stalin, NKVD agent Iosif Grigulevich orchestrates an unsuccessful assassination attempt on exiled Russian revolutionary Leon Trotsky in Coyoacán, Mexico.
1941 – World War II: Battle of the Atlantic: In the Battle of the Denmark Strait, the German battleship Bismarck sinks the pride of the Royal Navy, HMS Hood, killing all but three crewmen.
1944 – Börse Berlin building burns down after being hit in an air raid during World War II.
1944 – Congress of Përmet occurs which establishes a provisional government in Albania in areas under partisan control, the first independent Albanian government since 1939. In honor of this the national emblem of Albania inscribed this date from 1946 until 1992.
1948 – Arab–Israeli War: Egypt captures the Israeli kibbutz of Yad Mordechai, but the five-day effort gives Israeli forces time to prepare enough to stop the Egyptian advance a week later.
1956 – The first Eurovision Song Contest is held in Lugano, Switzerland.
1958 – United Press International is formed through a merger of the United Press and the International News Service.
1960 – Following the 1960 Valdivia earthquake, the largest ever recorded earthquake, Cordón Caulle begins to erupt.
1961 – American civil rights movement: Freedom Riders are arrested in Jackson, Mississippi, for “disturbing the peace” after disembarking from their bus.
1962 – Project Mercury: American astronaut Scott Carpenter orbits the Earth three times in the Aurora 7 space capsule.
1967 – Egypt imposes a blockade and siege of the Red Sea coast of Israel.
1967 – Belle de Jour, directed by Luis Buñuel, is released.
1976 – The Judgment of Paris takes place in France, launching California as a worldwide force in the production of quality wine.
1981 – Ecuadorian president Jaime Roldós Aguilera, his wife, and his presidential committee die in an aircraft accident while travelling from Quito to Zapotillo minutes after the president gave a famous speech regarding the 24 de mayo anniversary of the Battle of Pichincha.
1982 – Liberation of Khorramshahr: Iranians recapture of the port city of Khorramshahr from the Iraqis during the Iran–Iraq War.
1988 – Section 28 of the United Kingdom’s Local Government Act 1988, a controversial amendment stating that a local authority cannot intentionally promote homosexuality, is enacted.
1991 – Israel conducts Operation Solomon, evacuating Ethiopian Jews to Israel.
1992 – The last Thai dictator, General Suchinda Kraprayoon, resigns following pro-democracy protests.
1992 – The ethnic cleansing in Kozarac, Bosnia and Herzegovina begins when Serbian militia and police forces enter the town.
1993 – Eritrea gains its independence from Ethiopia.
1993 – Roman Catholic Cardinal Juan Jesús Posadas Ocampo and five other people are assassinated in a shootout at Miguel Hidalgo y Costilla Guadalajara International Airport in Mexico.
1994 – Four men are convicted of bombing the World Trade Center in New York in 1993; each one is sentenced to 240 years in prison.
1995 – While attempting to return to Leeds Bradford Airport in the United Kingdom, Knight Air Flight 816 crashes in Dunkeswick, North Yorkshire, killing all 12 people on board.
1999 – The International Criminal Tribunal for the former Yugoslavia in The Hague, Netherlands indicts Slobodan Milošević and four others for war crimes and crimes against humanity committed in Kosovo.
2000 – Israeli troops withdraw from southern Lebanon after 22 years of occupation.
2002 – Russia and the United States sign the Moscow Treaty.
2014 – A 6.4 magnitude earthquake occurs in the Aegean Sea between Greece and Turkey, injuring 324 people.
2014 – At least three people are killed in a shooting at Brussels’ Jewish Museum of Belgium.
2019 – Twenty-two students die in a fire in Surat (India).
2019 – Under pressure over her handling of Brexit, British Prime Minister Theresa May announces her resignation as Leader of the Conservative Party, effective as of June 7.
2022 – A mass shooting occurs at Robb Elementary School in Uvalde, Texas, United States, resulting in the deaths of 21 people, including 19 children.