15 May 1561

Prime Minister of Slovakia Robert Fico is hospitalised after an assassination attempt.

Three days before her seventeenth birthday, Jessica Watson arrived in Sydney after sailing non-stop and unassisted around the world.

Arsenal became the first football team in England's top flight to finish a season undefeated since Preston North End did so in 1888–1889.

A runaway train loaded with hazardous chemicals traveled driverless for 66 miles (106 km) through Ohio before being stopped near Kenton.

Vincent van Gogh's Portrait of Dr. Gachet was sold at auction at Christie's in New York for US$82.5 million, making it the world's most expensive painting at the time.

The Ryukyu Islands were returned to Japan by the United States, and the U.S. occupation government was abolished.

Police opened fire during a confrontation with a group of Jackson State College students, killing two students and injuring twelve others.

Disapproving of General Tôn Thất Đính's handling of the Buddhist Uprising, South Vietnamese prime minister Nguyễn Cao Kỳ ordered an attack on his forces and ousted Đính from his post.

The United Kingdom tested its first hydrogen bomb over Malden Island in Operation Grapple.

Don Murphy organized the first pinewood derby, an event for Cub Scouts of the Boy Scouts of America where wooden cars built by the scouts are raced.

The British Army directed fleeing Croatian soldiers to surrender to the Yugoslav Partisans, beginning the Bleiburg repatriations.

Mickey and Minnie Mouse made their film debuts in the animated cartoon Plane Crazy.

Jesse Washington, a teenage African-American farmhand, was lynched in Waco, Texas.

During a match, baseball star Ty Cobb enters the stands and assaults a fan who had heckled him, leading to his suspension.

Mexican Revolution: A force of Maderistas captured Torreón and proceeded to massacre 303 of the city's Chinese residents.

Russo-Japanese War: The Japanese battleships Hatsuse and Yashima sank after striking several mines off Port Arthur, China.

Pope Leo XIII issued the encyclical Rerum novarum, which addressed the condition of the working classes and is considered to be the foundation of modern Catholic social teaching.

Susan B. Anthony and Elizabeth Cady Stanton founded the National Woman Suffrage Association, breaking away from the American Equal Rights Association which they had also previously founded.

American Civil War: A small Confederate force, which included cadets from the Virginia Military Institute, forced the Union army out of the Shenandoah Valley.

Fertilisation of Orchids, the first book by Charles Darwin which demonstrated the power of natural selection in detail, was published.

Thieves stole 224 pounds (102 kg) of gold from a train travelling from London to Folkestone, England.

English astronomer Francis Baily observed Baily's beads (example pictured), a phenomenon during a solar eclipse in which the rugged topography of the lunar limb allows sunlight to shine through.

Bach led the first performance of his cantata Ich bin ein guter Hirt, BWV 85, about Jesus as the Good Shepherd.

Early English explorer Bartholomew Gosnold arrived on Cape Cod in present-day Massachusetts.

Pope Innocent IV issued the papal bull Ad extirpanda, authorizing the use of torture on heretics during the Medieval Inquisition.

Roman emperor Valentinian II (pictured) was found hanged in his residence in Vienne, in present-day France.