| | 1291 - Scottish nobles recognize the authority of King Edward I of England. |
| | 1497 - Amerigo Vespucci allegedly leaves Cádiz for his first voyage to the New World. |
| | 1503 - Christopher Columbus visits the Cayman Islands and names them Las Tortugas after the numerous sea turtles there. |
| | 1534 - Jacques Cartier visits Newfoundland. |
| | 1768 - John Wilkes is imprisoned for writing an article for the North Briton severely criticizing King George III. This action provokes rioting in London. |
| | 1774 - Louis XVI becomes King of France. |
| | 1775 - American Revolutionary War: Fort Ticonderoga is taken by a small force led by Colonel Benedict Arnold and Ethan Allen. |
| | 1775 - American Revolutionary War: Representatives from the 13 colonies of the United States meet in Philadelphia and raise the Continental Army to defend the new republic. They place it under command of Cavalier George Washington of Virginia. |
| | 1796 - First Coalition: Napoleon I of France wins a decisive victory against Austrian forces at Lodi bridge over the River Adda in Italy. The Austrians lose some 2,000 men. |
| | 1801 - First Barbary War: The Barbary pirates of Tripoli declare war on the United States. |
| | 1824 - National Gallery in London opens to the public. |
| | 1837 - Panic of 1837: New York City banks fail, and unemployment reaches record levels. |
| | 1857 - Indian Mutiny: In India, the first war of Independence begins. Sepoys revolt against the British Army. |
| | 1864 - American Civil War: Colonel Emory Upton leads a 10-regiment "Attack-in-depth" assault against the Confederate works at The Battle of Spotsylvania, which, though ultimately unsuccessful, would provide the idea for the massive assault against the Bloody Angle on May 12. Upton was wounded slightly but immediately is promoted to Brigadier general. |
| | 1865 - American Civil War: Jefferson Davis is captured by Union troops near Irwinville, Georgia. |
| | 1865 - American Civil War: Union soldiers ambush and mortally wound Confederate raider William Quantrill in Kentucky, who lingers until his death on June 6. |
| | 1865 - The trial against the Lincoln conspirators begins. |
| | 1869 - The First Transcontinental Railroad, linking the eastern and western United States, is completed at Promontory Summit, Utah (not Promontory Point, Utah) with the golden spike. |
| | 1872 - Victoria Woodhull becomes the first woman nominated for President of the United States. |
| | 1877 - Romania declares itself independent from Turkey, recognized on March 26, 1881 after the end of the Romanian independence war. |
| | 1908 - Mother's Day is observed for the first time (Andrew's Methodist Church in Grafton, West Virginia, USA). |
| | 1922 - The USA annexes the Kingman Reef. |
| | 1924 - J. Edgar Hoover is appointed the Director of the U.S. Federal Bureau of Investigation, and remains so until his death in 1972. |
| | 1933 - Censorship: In Germany, the Nazis stage massive public book burnings. |
| | 1940 - World War II: The first German bombs of the war fall on England at Chilham and Petham, in Kent. |
| | 1940 - World War II: Germany invades Belgium, the Netherlands, and Luxembourg. |
| | 1940 - World War II: Winston Churchill is appointed Prime Minister of the United Kingdom. |
| | 1940 - World War II: Iceland invaded by the United Kingdom. |
| | 1941 - World War II: The House of Commons in London is destroyed by the Luftwaffe in an air raid. |
| | 1941 - World War II: Rudolf Hess parachutes into Scotland in order to try and negotiate a peace deal between the United Kingdom and Nazi Germany. |
| | 1942 - Thai Phayap Army invaded the Shan States on May 10, during the Burma Campaign of World War II. |
| | 1954 - Bill Haley and the Comets release "Rock Around the Clock", the first rock and roll record to reach number one on the charts. |
| | 1960 - The nuclear submarine USS Triton completes the first underwater circumnavigation of the earth. |
| | 1969 - The Battle of Dong Ap Bia begins with an assault on Hill 937. It will ultimately become known as Hamburger Hill. |
| | 1969 - The first "Zip to Zap" rural outdoor rock concert at Zap, North Dakota, is ended prematurely as North Dakota National Guard is ordered to disperse the unruly crowd. |
| | 1970 - Bobby Orr flew through the air as he scored the game winning goal of a game in the Stanley Cup Finals. |
| | 1977 - Actress Joan Crawford (1905-1977) Born Lucille LeSeur in San Antonio Texas, Died of a heart attack related to cancer in New York City. |
| | 1979 - The Federated States of Micronesia becomes self-governing. |
| | 1981 - François Mitterrand takes office as the first Socialist President of France. |
| | 1988 - Michel Rocard becomes Prime Minister of France. |
| | 1993 - In Thailand, a fire at the Kader Toy Factory kills 188 workers, mostly young women. |
| | 1994 - The U.S. state of Illinois executes serial killer John Wayne Gacy for the murder of 33 young men and boys. |
| | 1994 - Nelson Mandela becomes the first black president of South Africa. |
| | 1994 - An annular eclipse of the sun is visible across much of North America. |
| | 1996 - A "rogue storm" near the summit of Mount Everest kills eight climbers, making this the deadliest day in the mountain's history. Among the dead are experienced climbers Rob Hall and Scott Fischer, both of whom were leading paid expeditions to the summit. |
| | 1997 - An earthquake near Ardekul in northeastern Iran kills at least 2,400 people. |
| | 2001 - The XFL ceases operation by Vince McMahon, Chairman of World Wrestling Federation Entertainment and NBC, citing rapidly decreasing ratings. |
| | 2001 - In Ghana, a stampede at a football game kills over 120 spectators. |
| | 2002 - FBI agent Robert Hanssen is given a life sentence without the possibility of parole for selling United States secrets to Moscow for $1.4 million in cash and diamonds. |
| | 2002 - Lynda Lyon Block is executed in Yellow Mama, the electric chair of Alabama. |
| | 2003 - Record shattering tornado activity during the May 2003 Tornado Outbreak Sequence. |
| | 2004 - Jeff Smith draws the last page of the Bone comic series. |
| | 2005 - A hand grenade allegedly thrown by Vladimir Arutinian lands about 100 feet from United States President George W. Bush while he is giving a speech to a crowd in Tbilisi, Georgia, but malfunctions and does not detonate. |