AD 65 – The freedman Milichus betrays Piso's plot to kill the Emperor Nero and all the conspirators are arrested.
531 – Battle of Callinicum: A Byzantine army under Belisarius is defeated by the Persians at Raqqa (northern Syria).
797 – Empress Irene organizes a conspiracy against her son, the Byzantine emperor Constantine VI. He is deposed and blinded. Shortly after, Constantine dies of his wounds; Irene proclaims herself basileus.
1012 – Martyrdom of Ælfheah in Greenwich, England.
1506 – The Lisbon Massacre begins, in which accused Jews are being slaughtered by Portuguese Catholics.
1529 – Beginning of the Protestant Reformation: After the Second Diet of Speyer bans Lutheranism, a group of rulers (German: Fürst) and independent cities protests the reinstatement of the Edict of Worms.
1539 – Treaty of Frankfurt signed
1608 – In Ireland: O'Doherty's Rebellion is launched by the Burning of Derry
1677 – The French army captures the town of Cambrai held by Spanish troops.
1713 – With no living male heirs, Charles VI, Holy Roman Emperor, issues the Pragmatic Sanction of 1713 to ensure that Habsburg lands and the Austrian throne would be inherited by his daughter, Maria Theresa (not actually born until 1717).
1770 – Captain James Cook, still holding the rank of lieutenant, sights the eastern coast of what is now Australia.
1770 – Marie Antoinette marries Louis XVI of France in a proxy wedding.
1775 – American Revolutionary War: The war begins with an American victory in Concord during the battles of Lexington and Concord.
1782 – John Adams secures the Dutch Republic's recognition of the United States as an independent government. The house which he had purchased in The Hague, Netherlands becomes the first American embassy.
1809 – An Austrian corps is defeated by the forces of the Duchy of Warsaw in the Battle of Raszyn, part of the struggles of the Fifth Coalition. On the same day the Austrian main army is defeated by a First French Empire Corps led by Louis-Nicolas Davout at the Battle of Teugen-Hausen in Bavaria, part of a four-day campaign that ended in a French victory.
1810 – Venezuela achieves home rule: Vicente Emparán, Governor of the Captaincy General is removed by the people of Caracas and a junta is installed.
1818 – French physicist Augustin Fresnel signs his preliminary "Note on the Theory of Diffraction" (deposited on the following day). The document ends with what we now call the Fresnel integrals.
1839 – The Treaty of London establishes Belgium as a kingdom and guarantees its neutrality.
1861 – American Civil War: Baltimore riot of 1861: A pro-Secession mob in Baltimore attacks United States Army troops marching through the city.
1903 – The Kishinev pogrom in Kishinev (Bessarabia) begins, forcing tens of thousands of Jews to later seek refuge in Palestine and the Western world.
1927 – Mae West is sentenced to ten days in jail for obscenity for her play Sex.
1942 – World War II: In Poland, the Majdan-Tatarski ghetto is established, situated between the Lublin Ghetto and a Majdanek subcamp.
1943 – World War II: In Poland, the Warsaw Ghetto Uprising begins, after German troops enter the Warsaw Ghetto to round up the remaining Jews.
1943 – Albert Hofmann deliberately doses himself with LSD for the first time, three days after having discovered its effects on April 16.
1956 – Actress Grace Kelly marries Prince Rainier of Monaco.
1960 – Students in South Korea hold a nationwide pro-democracy protest against president Syngman Rhee, eventually forcing him to resign.
1971 – Sierra Leone becomes a republic, and Siaka Stevens the president.
1971 – Launch of Salyut 1, the first space station.
1971 – Charles Manson is sentenced to death (later commuted to life imprisonment) for conspiracy in the Tate–LaBianca murders.
1973 – The Portuguese Socialist Party is founded in the German town of Bad Münstereifel.
1975 – India's first satellite Aryabhata launched in orbit from Kapustin Yar, Russia.
1984 – Advance Australia Fair is proclaimed as Australia's national anthem, and green and gold as the national colours.
1985 – Two hundred ATF and FBI agents lay siege to the compound of the white supremacist survivalist group The Covenant, The Sword, and the Arm of the Lord in Arkansas; the CSA surrenders two days later.
1987 – The Simpsons first appear as a series of shorts on The Tracey Ullman Show, first starting with Good Night.
1989 – A gun turret explodes on the USS Iowa, killing 47 sailors.
1993 – The 51-day FBI siege of the Branch Davidian building in Waco, Texas, USA, ends when a fire breaks out. 76 Davidians including 18 children under the age of 10 died in the fire.
1995 – Oklahoma City bombing: The Alfred P. Murrah Federal Building in Oklahoma City, USA, is bombed, killing 168 people including 19 children under the age of 6.
1999 – The German Bundestag returns to Berlin.
2005 – Cardinal Joseph Ratzinger is elected to the papacy and becomes Pope Benedict XVI.
2011 – Fidel Castro resigns as First Secretary of the Communist Party of Cuba after holding the title since July 1961.
2013 – Boston Marathon bombing suspect Tamerlan Tsarnaev is killed in a shootout with police. His brother Dzhokhar is later captured hiding in a boat inside a backyard in the suburb of Watertown.
