Former Formula One driver Takuma Sato wins his first Indianapolis 500, the first Japanese and Asian driver to do so. Double world champion Fernando Alonso retires from an engine issue in his first entry of the event.
Harambe, a gorilla, is shot to death after grabbing a three-year-old boy in his enclosure at the Cincinnati Zoo and Botanical Garden, resulting in widespread criticism and sparking various internet memes.
The Arkankergen massacre in Kazakhstan's Alakol District kills 15 people.
Malta votes on the introduction of divorce; the proposal was approved by 53% of voters, resulting in a law allowing divorce under certain conditions being enacted later in the year.
In West Bengal, India, the Jnaneswari Express train derailment and subsequent collision kills 148 passengers.
The first meeting of the Constituent Assembly of Nepal formally declares Nepal a republic, ending the 240-year reign of the Shah dynasty.
The Iraqi Governing Council chooses Ayad Allawi, a longtime anti-Saddam Hussein exile, as prime minister of Iraq's interim government.
Peter Hollingworth resigns as Governor-General of Australia following criticism of his handling of child sexual abuse allegations during his tenure as Anglican Archbishop of Brisbane.
The last steel girder is removed from the original World Trade Center site. Cleanup duties officially end with closing ceremonies at Ground Zero in Manhattan, New York City.
In Milan, Italy, after 22 years of restoration work, Leonardo da Vinci's masterpiece The Last Supper is put back on display.
Nuclear testing: Pakistan responds to a series of nuclear tests by India with five of its own codenamed Chagai-I, prompting the United States, Japan, and other nations to impose economic sanctions. Pakistan celebrates Youm-e-Takbir annually.
U.S. President Bill Clinton's former business partners in the Whitewater land deal, Jim McDougal and Susan McDougal, and the Governor of Arkansas, Jim Guy Tucker, are convicted of fraud.
The 7.0 Mw Neftegorsk earthquake shakes the former Russian settlement of Neftegorsk with a maximum Mercalli intensity of IX (Violent). Total damage was $64.1–300 million, with 1,989 deaths and 750 injured. The settlement was not rebuilt.
The capital city of Addis Ababa falls to the Ethiopian People's Revolutionary Democratic Front, ending both the Derg regime in Ethiopia and the Ethiopian Civil War.
An 18-year-old West German pilot, Mathias Rust, evades Soviet Union air defences and lands a private plane in Red Square in Moscow, Russia.
Konstantinos Karamanlis signs the full treaty of the accession of Greece with the European Economic Community.
The Beverly Hills Supper Club in Southgate, Kentucky, is engulfed by fire, killing 165 people inside.
Fifteen West African countries sign the Treaty of Lagos, creating the Economic Community of West African States.
At Brampton Centennial Secondary School, student Michael Slobodian kills two people and injures 13 others before committing suicide.
Northern Ireland's power-sharing Sunningdale Agreement collapses following a general strike by loyalists.
Garuda Indonesian Airways Flight 892 crashes near Nala Sopara in India, killing 30.
The Palestine Liberation Organization (PLO) is founded, with Yasser Arafat elected as its first leader.
Peter Benenson's article The Forgotten Prisoners is published in several internationally read newspapers. This will later be thought of as the founding of the human rights organization Amnesty International.
Cuban Revolution: Fidel Castro's 26th of July Movement, heavily reinforced by Frank Pais Militia, overwhelm an army post in El Uvero.
Daniel François Malan is elected as Prime Minister of South Africa. He later goes on to implement Apartheid.
World War II: Belgium surrenders to Nazi Germany to end the Battle of Belgium.
World War II: Norwegian, French, Polish and British forces recapture Narvik in Norway. This is the first Allied infantry victory of the War.
Volkswagen, the German automobile manufacturer, is founded.
Alan Turing submits On Computable Numbers for publication.
Near Callander, Ontario, Canada, the Dionne quintuplets are born to Oliva and Elzire Dionne; they will be the first quintuplets to survive infancy.
In the Netherlands, construction of the Afsluitdijk is completed and the Zuiderzee bay is converted to the freshwater IJsselmeer.
The 28 May 1926 coup d'état: Ditadura Nacional is established in Portugal to suppress the unrest of the First Republic.
The Azerbaijan Democratic Republic and the First Republic of Armenia declare their independence.
Russo-Japanese War: The Battle of Tsushima ends with the destruction of the Russian Baltic Fleet by Admiral Tōgō Heihachirō and the Imperial Japanese Navy.
In San Francisco, John Muir organizes the Sierra Club.
U.S. President Andrew Jackson signs the Indian Removal Act which denies Native Americans their land rights and forcibly relocates them.
In Guadeloupe, 400 rebellious slaves, led by Louis Delgrès, blow themselves up rather than submit to Napoleon's troops.
French and Indian War: In the first engagement of the war, Virginia militia under the 22-year-old Lieutenant colonel George Washington defeat a French reconnaissance party in the Battle of Jumonville Glen in what is now Fayette County in southwestern...
English Civil War: Bolton Massacre by Royalist troops under the command of James Stanley, 7th Earl of Derby.
The Spanish Armada, with 130 ships and 30,000 men, sets sail from Lisbon, Portugal, heading for the English Channel. (It will take until May 30 for all ships to leave port.)
The Archbishop of Canterbury, Thomas Cranmer, declares the marriage of King Henry VIII of England to Anne Boleyn valid.
Marriage of Byzantine Emperor John V Palaiologos and Helena Kantakouzene.
Avignonet massacre: A group of Cathars, with the probable connivance of Count Raymond VII of Toulouse, murdered the inquisitor William Arnaud and eleven of his companions.
English king Æthelstan begins his invasion of Scotland with.
Battle of Hulao: Li Shimin, the son of the Chinese emperor Gaozu, defeats the numerically superior forces of Dou Jiande near the Hulao Pass (Henan). This victory decides the outcome of the civil war that followed the Sui dynasty's collapse in favour...
A solar eclipse occurs, as predicted by the Greek philosopher and scientist Thales, while Alyattes is battling Cyaxares in the Battle of the Eclipse, leading to a truce. This is one of the cardinal dates from which other dates can be calculated. It i...