8 May 1561

Cardinal Robert Francis Prevost was elected as Pope Leo XIV (pictured), making him the first pope born in the United States, the first to hold either U.S. or Peruvian citizenship, the first from the Order of Saint Augustine, and the second from the Americas after his immediate predecessor, Pope Francis.

A British Special Air Service unit ambushed a Provisional Irish Republican Army (IRA) unit in Loughgall, Northern Ireland, killing eight IRA members and one civilian.

The Soviet Union announced the boycott of the Summer Olympics in Los Angeles, citing security concerns.

Great American Revolution opened at Six Flags Magic Mountain, California.

Construction workers attacked students and others who were protesting the Vietnam War in New York City.

In Huế, South Vietnam, soldiers opened fire into a crowd of Buddhists protesting against a government ban on the flying of the Buddhist flag on Phật Đản, killing nine and sparking the Buddhist crisis.

South Vietnamese president Ngô Đình Diệm began a state visit to the United States, his regime's main sponsor.

The Tollund Man, a naturally mummified corpse, was discovered in a peat bog near Silkeborg, Denmark.

A parade in Sétif, French Algeria, celebrating the end of World War II in Europe became a riot and was followed by reprisals, carried out by colonial authorities over the following weeks, that killed thousands.

World War II: The Axis launched a major counteroffensive, turning the tide of the Battle of the Kerch Peninsula.

French aviators Charles Nungesser and François Coli aboard the biplane L'Oiseau Blanc took off from Paris, attempting to make the first non-stop flight to New York, only to disappear before arrival.

A train derailed and caught fire near Versailles, France, killing at least 52 people.

Greek War of Independence: At the Battle of Gravia Inn, a 120-man Greek force led by Odysseas Androutsos repulsed an Ottoman army of 8,000 soldiers.

First English Civil War: The first siege of Wardour Castle ended after six days with the surrender of the Royalist garrison under Lady Blanche Arundell

Julian of Norwich experienced religious visions, later recorded in Revelations of Divine Love, the earliest surviving English-language work attributed to a woman.

The 2025 papal conclave elects Cardinal Robert Francis Prevost, taking the name Leo XIV as the 267th Pope of the Catholic Church.

British 17-year-old Isabelle Holdaway is reported to be the first patient ever to receive a genetically modified phage therapy to treat a drug-resistant infection.

China Southern Airlines Flight 3456 crashes on approach into Bao'an International Airport, killing 35 people.

A fire at Illinois Bell's Hinsdale Central Office triggers an extended 1AESS network outage once considered to be the "worst telecommunications disaster in US telephone industry history".

The SAS kills eight Provisional Irish Republican Army volunteers and a civilian during an ambush in Loughgall, Northern Ireland.

The Soviet Union announces a boycott upon the Summer Olympics at Los Angeles, later joined by 14 other countries.

The Thames Barrier is officially opened, preventing the floodplain of most of Greater London from being flooded except under extreme circumstances.

The World Health Organization confirms the eradication of smallpox.

The first ascent of Mount Everest without supplemental oxygen, by Reinhold Messner and Peter Habeler.