28 BC – A sunspot is observed by Han dynasty astronomers during the reign of Emperor Cheng of Han, one of the earliest dated sunspot observations in China.
AD 70 – Siege of Jerusalem: Titus, son of emperor Vespasian, opens a full-scale assault on Jerusalem and attacks the city's Third Wall to the northwest.
1291 – Scottish nobles recognize the authority of Edward I of England pending the selection of a king.
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 turtles there.
1534 – Jacques Cartier visits Newfoundland.
1655 – England, with troops under the command of Admiral William Penn and General Robert Venables, annexes Jamaica from Spain.
1688 – King Narai nominates his daughter Sudawadi to succeed him with Constantine Phaulkon, Mom Pi and Phetracha acting as regents. The ensuing revolution leads to the Ayutthaya Kingdom severing all ties with Europe.
1768 – John Wilkes is imprisoned for writing an article for The North Briton severely criticizing King George III. This action provokes rioting in London.
1773 – The Parliament of Great Britain passes the Tea Act, designed to save the British East India Company by granting it a monopoly on the North American tea trade.
1774 – Louis XVI and Marie Antoinette become King and Queen of France.
1775 – American Revolutionary War: A small Colonial militia led by Ethan Allen and Colonel Benedict Arnold captures Fort Ticonderoga.
1775 – American Revolutionary War: Representatives from the Thirteen Colonies begin the Second Continental Congress in Philadelphia.
1796 – War of the First Coalition: Napoleon I of France wins a victory against Austrian forces at Lodi bridge over the Adda River in Italy. The Austrians lose some 2,000 men.
1801 – First Barbary War: The Barbary pirates of Tripoli declare war on the United States of America.
1824 – The National Gallery in London opens to the public.
1833 – The desecration of the grave of the viceroy of southern Vietnam Lê Văn Duyệt by Emperor Minh Mạng provokes his adopted son to start a revolt.
1837 – Panic of 1837: New York City banks fail, and unemployment reaches record levels.
1849 – Astor Place Riot: A riot breaks out at the Astor Opera House in Manhattan, New York City over a dispute between actors Edwin Forrest and William Charles Macready, killing at least 25 and injuring over 120.
1857 – Indian Rebellion of 1857: In India, the first war of Independence begins. Sepoys mutiny against their commanding officers at Meerut.
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 is slightly wounded but is immediately promoted to brigadier general.
1865 – American Civil War: Jefferson Davis is captured by U.S. troops near Irwinville, Georgia.
1865 – American Civil War: In Kentucky, Union soldiers ambush and mortally wound Confederate raider William Quantrill, who lingers until his death on June 6.
1866 – Karl of Hohenzollern-Sigmaringen is crowned the Ruling Prince of the United Principalities of Romania.
1869 – The First Transcontinental Railroad, linking the eastern and western United States, is completed at Promontory Summit, Utah with the golden spike.
1872 – Victoria Woodhull becomes the first woman nominated for President of the United States.
1876 – The Centennial Exposition is opened in Philadelphia by U.S. President Ulysses S. Grant and Brazilian Emperor Dom Pedro II.
1877 – Romania declares itself independent from the Ottoman Empire following the Senate adoption of Mihail Kogălniceanu's Declaration of Independence.
1904 – The Horch & Cir. Motorwagenwerke AG is founded. It would eventually become the Audi company.
1908 – Mother's Day is observed for the first time in the United States, in Grafton, West Virginia.
1916 – Sailing in the lifeboat James Caird, Ernest Shackleton arrives at South Georgia after a journey of 800 nautical miles from Elephant Island.
1922 – The United States annexes the Kingman Reef.
1924 – J. Edgar Hoover is appointed first Director of the United States' Federal Bureau of Investigation (FBI), and remains so until his death in 1972.
1933 – Censorship: In Germany, the Nazis stage massive public book burnings.
1940 – World War II: German fighters accidentally bomb the German city of Freiburg.
1940 – World War II: German raids on British shipping convoys and military airfields begin.
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 following the resignation of Neville Chamberlain.
1940 – World War II: Invasion of Iceland by the United Kingdom.
1941 – World War II: The House of Commons in London is damaged by the Luftwaffe in an air raid.
1941 – World War II: Rudolf Hess parachutes into Scotland to try to negotiate a peace deal between the United Kingdom and Nazi Germany.
1942 – World War II: The Thai Phayap Army invades the Shan States during the Burma Campaign.
1946 – First successful launch of an American V-2 rocket at White Sands Proving Ground.
1948 – The Republic of China implements "temporary provisions" granting President Chiang Kai-shek extended powers to deal with the Communist uprising; they will remain in effect until 1991.
1954 – Bill Haley & His Comets release "Rock Around the Clock", the first rock and roll record to reach number one on the Billboard charts.
1960 – The nuclear submarine USS Triton completes Operation Sandblast, the first underwater circumnavigation of the earth.
1962 – Marvel Comics publishes the first issue of The Incredible Hulk.
1969 – Vietnam War: The Battle of Dong Ap Bia begins with an assault on Hill 937. It will ultimately become known as Hamburger Hill.
1970 – Bobby Orr scores "The Goal" to win the 1970 Stanley Cup Finals, for the Boston Bruins' fourth NHL championship in their history.
1972 – In the Vietnam War, the US had two fighter ace crews. The USAF's Ritchie and DeBellevue scored their first kill while the USN's Cunningham and Driscoll scored their third, fourth and fifth kills.
1975 – Sony introduces the Betamax videocassette recorder in Japan.
1997 – The 7.3 Mw Qayen earthquake strikes Iran's Khorasan Province, killing 1,567, injuring over 2,300, leaving 50,000 homeless, and damaging or destroying over 15,000 homes.
2002 – FBI agent Robert Hanssen is sentenced to life imprisonment without the possibility of parole for selling United States secrets to Russia for $1.4 million in cash and diamonds.
2005 – A hand grenade thrown by Vladimir Arutyunian lands about 65 feet (20 meters) from U.S. President George W. Bush while he is giving a speech to a crowd in Tbilisi, Georgia, but it malfunctions and does not detonate.
2012 – The Damascus bombings are carried out using a pair of car bombs detonated by suicide bombers outside of a military intelligence complex in Damascus, Syria, killing 55 people and injuring 400 others.
2013 – One World Trade Center becomes the tallest building in the Western Hemisphere.