Editing May 21 (section)

===1901–present===
*[[1904]] &ndash; The [[FIFA|Fédération Internationale de Football Association]] (FIFA) is founded in Paris.
*[[1911]] &ndash; [[President of Mexico]] [[Porfirio Díaz]] and the revolutionary [[Francisco Madero]] sign the [[Treaty of Ciudad Juárez]] to put an end to the fighting between the forces of both men, concluding the initial phase of the [[Mexican Revolution]].
*[[1917]] &ndash; The [[Commonwealth War Graves Commission|Imperial War Graves Commission]] is established through [[royal charter]] to mark, record, and maintain the graves and places of commemoration of the [[Commonwealth of Nations|British Empire's]] military forces.<ref>{{cite book|last=Summers|first=Julie|title=Remembered: The History of the Commonwealth War Graves Commission|location=London|publisher=Merrell|year=2007|isbn=9781858943749|pages=16, 18|postscript=none}}; {{cite book|last1=Shortt|first1=Adam|last2=Rowe|first2=L.S.|title=Preliminary Economic Studies of the War. Volume 8|location=New York|publisher=Oxford University Press|date=1918|url=https://books.google.com/books?id=knILAQAAIAAJ|pages=92=93|postscript=none}}; {{cite book|last=Gilbert|first=Martin|title=The First World War: A Complete History|location=New York|publisher=Henry Holt and Company|date=1994|isbn=9780805015409|url=https://books.google.com/books?id=4povVJ-jkCoC|pages=325=326}}</ref>
*  1917   &ndash; The [[Great Atlanta fire of 1917]] causes $5.5&nbsp;million in damages, destroying some 300 acres including 2,000 homes, businesses and churches, displacing about 10,000 people but leading to only one fatality (due to heart attack).
*[[1924]] &ndash; [[University of Chicago]] students [[Leopold and Loeb|Richard Loeb and Nathan Leopold, Jr.]] murder 14-year-old [[Bobby Franks]] in a "[[thrill killing]]".
*[[1925]] &ndash; The opera ''[[Doktor Faust]]'', unfinished when composer [[Ferruccio Busoni]] died, is premiered [[Semperoper|in Dresden]].<ref>[https://almanac-gherardo-casaglia.com/index.php?Giorno=21&Mese=05&Anno=1925&Testo=Doktor_Faust&Parola=Stringa 21 Maggio 1925, Giovedì] almanac-gherardo-casaglia.com</ref>
*[[1927]] &ndash; [[Charles Lindbergh]] touches down at [[Le Bourget Field]] in Paris, completing the world's first solo nonstop flight across the Atlantic Ocean.
*[[1932]] &ndash; Bad weather forces [[Amelia Earhart]] to land in a pasture in [[Derry]], Northern Ireland, and she thereby becomes the first woman to fly solo across the Atlantic Ocean.
*[[1934]] &ndash; [[Oskaloosa, Iowa]], becomes the first municipality in the United States to fingerprint all of its citizens.
*[[1936]] &ndash; [[Sada Abe]] is arrested after wandering the streets of Tokyo for days with her dead lover's severed genitals in her handbag. Her story soon becomes one of Japan's most notorious scandals.
*[[1937]] &ndash; A [[Soviet and Russian manned drifting ice stations|Soviet station]], [[North Pole-1]], becomes the first scientific research settlement to operate on the [[drift ice]] of the Arctic Ocean.
*[[1939]] &ndash; The Canadian [[National War Memorial (Canada)|National War Memorial]] is unveiled by [[George VI|King George VI]] and [[Queen Elizabeth The Queen Mother|Queen Elizabeth]] in [[Ottawa]], Ontario, Canada.
*[[1946]] &ndash; Physicist [[Louis Slotin]] is fatally irradiated in a [[criticality incident]] during an experiment with the [[demon core]] at [[Los Alamos National Laboratory]].
*[[1951]] &ndash; The opening of the [[Ninth Street Show]], otherwise known as the [[9th Street Art Exhibition]]: A gathering of a number of notable artists, and the stepping-out of the post war New York [[avant-garde]], collectively known as the [[New York School (art)|New York School]].
*[[1961]] &ndash; [[American civil rights movement]]: [[Alabama]] Governor [[John Malcolm Patterson]] declares [[martial law]] in an attempt to restore order after [[race riot]]s break out.
*[[1966]] &ndash; The [[Ulster Volunteer Force]] declares war on the [[Irish Republican Army (1922–69)|Irish Republican Army]] in [[Northern Ireland]].
*[[1969]] &ndash; Civil unrest in [[Rosario]], Argentina, known as ''[[Rosariazo]]'', following the death of a 15-year-old student.
*[[1972]] &ndash; [[Michelangelo]]'s ''[[Pietà (Michelangelo)|Pietà]]'' in [[St. Peter's Basilica]] in Rome is damaged by a [[vandalism|vandal]], the mentally disturbed Hungarian geologist [[Laszlo Toth]].
*[[1976]] &ndash; Twenty-nine people are killed in the [[Yuba City bus disaster]] in [[Martinez, California]].
*[[1979]] &ndash; [[White Night riots]] in [[San Francisco]] following the [[manslaughter]] conviction of [[Dan White]] for the assassinations of [[George Moscone]] and [[Harvey Milk]].
*[[1981]] &ndash; The Italian government releases the membership list of [[Propaganda Due]], an illegal pseudo-[[Freemasonry|Masonic lodge]] that was implicated in numerous Italian crimes and mysteries.
*  1981   &ndash; [[Transamerica Corporation]] agrees to sell [[United Artists]] to [[Metro-Goldwyn-Mayer]] for $380&nbsp;million after the box office failure of the 1980 film ''[[Heaven's Gate (film)|Heaven's Gate]]''.<ref>{{cite news|last=Cole|first=Robert J.|title=M-G-M Is Reported Purchasing United Artists for $350 Million|work=The New York Times|date=May 16, 1981|access-date=May 21, 2019|url=https://www.nytimes.com/1981/05/16/world/m-g-m-is-reported-purchasing-united-artists-for-350-million.html|postscript=none}}; {{cite news|title=M-G-M to Buy United Artists|work=The New York Times|date=May 22, 1981|access-date=May 21, 2019|url=https://www.nytimes.com/1981/05/22/business/m-g-m-to-buy-united-artists.html|postscript=none}}; {{cite book|last=Kermode|first=Mark|chapter=''Heaven's Gate'' and United Artists|title=Contemporary American Cinema|editor-last1=Hammond|editor-first1=Michael|editor-last2=Williams|editor-first2=Linda Ruth|location=Maidenhead, Berk., UK|publisher=Open University Press|date=2006|isbn=9780335218318|url=https://books.google.com/books?id=aD1EBgAAQBAJ|page=246}}</ref>
*[[1982]] &ndash; [[Falklands War]]: A British amphibious assault during [[Operation Sutton]] leads to the [[Battle of San Carlos (1982)|Battle of San Carlos]].
*[[1988]] &ndash; [[Margaret Thatcher]] holds her controversial [[Sermon on the Mound]] before the [[General Assembly of the Church of Scotland]].<ref>{{Cite web|url=https://www.margaretthatcher.org/document/107246|title=Speech to General Assembly of the Church of Scotland|date=1988-05-25|access-date=25 May 2018|website=Margaret Thatcher Foundation|last=Thatcher|first=Margaret}}</ref><ref>{{Cite book|title=God, Man & Mrs Thatcher: A Critique of Mrs Thatcher's Address to the General Assembly of the Church of Scotland|last=Raban|first=Jonathan|publisher=Chatto and Widus|date=1989|isbn=0-7011-3470-4|publication-place=London|authorlink=Jonathan Raban}}</ref>
*[[1991]] &ndash; Former Indian [[Prime Minister of India|Prime Minister]] [[Rajiv Gandhi]] is [[Assassination of Rajiv Gandhi|assassinated]] by a female suicide bomber near [[Chennai|Madras]].
*  1991   &ndash; [[Mengistu Haile Mariam]], president of the [[People's Democratic Republic of Ethiopia]], flees [[Ethiopia]], effectively bringing the [[Ethiopian Civil War]] to an end.
*[[1992]] &ndash; After 30 seasons [[Johnny Carson]] hosted his penultimate episode and last featuring guests ([[Robin Williams]] and [[Bette Midler]]) of ''[[The Tonight Show]]''.
*[[1994]] &ndash; The [[Democratic Republic of Yemen]] unsuccessfully attempts to secede from the [[Republic of Yemen]]; a [[Yemeni Civil War (1994)|war]] breaks out.
*[[1996]] &ndash; The ferry {{MV|Bukoba}} sinks in [[Tanzania]]n waters on [[Lake Victoria]], killing nearly 1,000.
*[[1996]] &ndash; The seven [[Trappists|Trappist]] monks of [[Abbey of Our Lady of Atlas|Tibhirine]] that were abducted on March 27 [[Murder of the monks of Tibhirine|are killed]] under uncertain circumstances.<ref>{{cite web |last1=Whitney |first1=Craig R. |title=7 French Monks Reported Killed By Islamic Militants in Algeria |url=https://www.nytimes.com/1996/05/24/world/7-french-monks-reported-killed-by-islamic-militants-in-algeria.html |website=The New York Times |access-date=12 January 2024 |date=24 May 1996}}</ref><ref name=France24>{{cite news|url=http://www.france24.com/en/20090706-algerian-army-accused-french-monk-massacre|title=Algerian army accused in massacre of French monks|publisher=France 24|date=7 July 2009|url-status=dead|archive-url=https://web.archive.org/web/20090707230903/http://www.france24.com/en/20090706-algerian-army-accused-french-monk-massacre|archive-date=7 July 2009}}</ref>
*[[1998]] &ndash; In [[Miami]], five [[abortion clinic]]s are attacked by a [[butyric acid]] attacker.
*  1998   &ndash; President [[Suharto]] of [[Indonesia]] resigns following the killing of students from [[Trisakti shootings|Trisakti University]] earlier that week by security forces and growing mass protests in [[Jakarta]] against his ongoing corrupt rule. 
*[[2000]] &ndash; Nineteen people are killed in a [[2000 East Coast Aviation Services British Aerospace Jetstream crash|plane crash]] in [[Wilkes-Barre, Pennsylvania]].<ref>{{Cite web |last=Ranter |first=Harro |title=ASN Aircraft accident British Aerospace 3102 Jetstream 31 N16EJ Wilkes-Barre, PA |url=https://aviation-safety.net/database/record.php?id=20000521-0 |access-date=2022-05-21 |website=aviation-safety.net |publisher=[[Aviation Safety Network]]}}</ref> 
*[[2001]] &ndash; French [[Christiane Taubira|Taubira law]] is enacted, officially recognizing the [[Atlantic slave trade]] and [[slavery]] as [[crimes against humanity]].
*[[2003]] &ndash; The 6.8 {{M|w}} [[2003 Boumerdès earthquake|Boumerdès earthquake]] shakes northern [[Algeria]] with a maximum [[Mercalli intensity scale|Mercalli intensity]] of X (''Extreme''). More than 2,200 people were killed and a moderate tsunami sank boats at the [[Balearic Islands]].
*[[2005]] &ndash; The tallest [[roller coaster]] in the world, [[Kingda Ka]] opens at [[Six Flags Great Adventure]] in [[Jackson Township, New Jersey]].
*[[2006]] &ndash; The [[Republic of Montenegro]] holds a [[Montenegrin independence referendum, 2006|referendum]] proposing independence from the [[State Union of Serbia and Montenegro]]; 55% of Montenegrins vote for independence.
*[[2010]] &ndash; JAXA, the [[Japan Aerospace Exploration Agency]], launches the [[solar-sail]] spacecraft [[IKAROS]] aboard an [[H-IIA]] rocket. The vessel would make a Venus flyby late in the year.
*[[2011]] &ndash; Radio broadcaster [[Harold Camping]] predicted that the [[2011 end times prediction|world would end]] on this date. 
*[[2012]] &ndash; A [[Qafa e Vishës bus accident|bus accident]] near [[Himara|Himara, Albania]] kills 13 people and injures 21 others.
*  2012   &ndash; [[2012 Sana'a bombing|A suicide bombing]] kills more than 120 people in [[Sana'a|Sana'a, Yemen]].
*[[2014]] &ndash; [[2014 Taipei Metro attack|Random killings]] occurred on the [[Bannan Line]] of the [[Taipei MRT]], killing four and injuring 24.<ref name="Strait">{{cite news|title=Four killed, 21 wounded in Taipei subway knife attack|url=http://www.straitstimes.com/news/asia/east-asia/story/three-killed-25-wounded-taiwan-subway-knife-attack-20140521|work=[[The Straits Times]]|accessdate=21 May 2014|agency=[[Agence France-Presse]]|date=21 May 2014}}</ref>
*[[2017]] &ndash; [[Ringling Bros. and Barnum & Bailey Circus]] performed their final show at Nassau Veterans Memorial Coliseum.
*[[2024]] – The [[Greenfield tornado]] kills 5 and injures 35 across rural [[Iowa]], United States.<ref>{{cite web |url=https://www.weather.gov/dmx/2024-May-21-Iowa-TornadoesWindsFlooding |title=Event Summary May 21, 2024 Tornadoes, Winds and Flash Flooding |publisher=[[National Weather Service Des Moines, Iowa]] |access-date=11 February 2025 }}</ref> Wind speeds in excess of {{cvt|300|mph|km/h}} are estimated from measurements for the third time in history.<ref>{{cite web |title=Flexible Array of Radars and Mesonets (FARM) statement concerning preliminary peak wind speed determinations based on Doppler On Wheels (DOW) data obtained in the Greenfield, Iowa tornado of 21 May 2024 |url=http://www.farmfacility.org/pdf/best-greenfield-windspeed-note-2024-0623bp2.pdf |publisher=[[University of Illinois Urbana-Champaign|University of Illinois]] |access-date=24 June 2024 |archive-url=https://web.archive.org/web/20240624040232/http://publish.illinois.edu/dowfacility-upgrade/files/2024/06/best-greenfield-windspeed-note-2024-0623bp2.pdf |archive-date=24 June 2024 |location=[[Champaign–Urbana metropolitan area]] |date=23 June 2024 |url-status=live}}</ref>