* 37 – The Roman Senate annuls Tiberius's will and proclaims Caligula emperor.
* 235 – Emperor Alexander Severus and his mother Julia Mamaea are murdered by legionaries near Moguntiacum (modern Mainz). The Severan dynasty ends.
* 1229 – Frederick II, Holy Roman Emperor declares himself King of Jerusalem during the Sixth Crusade.
* 1241 – Mongols overwhelm Polish armies in Kraków in the Battle of Chmielnik and plunder the city.
* 1314 – Jacques de Molay, the 23rd and the last Grand Master of the Knights Templar, is burned at the stake.
* 1438 – Albert II of Habsburg becomes Holy Roman Emperor.
* 1608 – Susenyos is formally crowned Emperor of Ethiopia.
* 1673 – John Berkeley, 1st Baron Berkeley of Stratton sells his part of New Jersey to the Religious Society of Friends, commonly known as Quakers.
* 1766 – American Revolution: The British Parliament repeals the Stamp Act.
* 1793 – The first republican state in Germany, the Republic of Mainz, is declared by Andreas Joseph Hofmann.
* 1834 – Six farm labourers from Tolpuddle, Dorset, England are sentenced to be transported to Australia for forming a trade union.
* 1850 – American Express is founded by Henry Wells and William Fargo.
* 1865 – American Civil War: The Congress of the Confederate States adjourns for the last time.
* 1871 – Declaration of the Paris Commune; President of the French Republic, Adolphe Thiers, orders evacuation of Paris.
* 1874 – Hawaii signs a treaty with the United States granting exclusive trading rights.
* 1893 – Former Governor General Lord Stanley pledges to donate a silver challenge cup, later named after him, as an award for the best hockey team in Canada; originally presented to amateur champions, the Stanley Cup has been awarded to the top pro team since 1910, and since 1926, only to National Hockey League teams.
* 1906 – Traian Vuia flies a heavier-than-air aircraft for 20 meters at 1 meter altitude.
* 1913 – King George I of Greece is assassinated in the recently liberated city of Thessaloniki.
* 1915 – World War I: Massive naval attack in Battle of Gallipoli. Three battleships are sunk during a failed British and French naval attack on the Dardanelles.
* 1921 – The second Peace of Riga between Poland and Soviet Union.
* 1922 – In India, Mohandas Gandhi is sentenced to six years in prison for civil disobedience. He would serve only 2 years.
* 1925 – The Tri-State Tornado hits the Midwestern states of Missouri, Illinois, and Indiana, killing 695 people.
* 1937 – The New London School explosion kills three hundred, mostly children.
* 1937 – Spanish Civil War: Spanish Republican forces defeat the Italians at the Battle of Guadalajara.
* 1937 – The human-powered aircraft, Pedaliante, flies 1 kilometre (0.62 mi) outside Milan.
* 1938 – Mexico nationalizes all foreign-owned oil properties within its borders.
* 1940 – World War II: Axis Powers – Adolf Hitler and Benito Mussolini meet at the Brenner Pass in the Alps and agree to form an alliance against France and the United Kingdom.
* 1942 – The War Relocation Authority is established in the United States to take Japanese Americans into custody.
* 1944 – The eruption of Mount Vesuvius in Italy kills 26 and causes thousands to flee their homes.
* 1945 – World War II: 1,250 American bombers attack Berlin.
* 1946 – Diplomatic relations between Switzerland and the Soviet Union are established.
* 1948 – Soviet consultants leave Yugoslavia in the first sign of a Tito-Stalin split.
* 1953 – An earthquake hits western Turkey, killing 250.
* 1959 – President Dwight D. Eisenhower signs a bill into law allowing for Hawaiian statehood, which would become official on August 21.
* 1962 – The Evian Accords put an end to the Algerian War of Independence, which began in 1954.
* 1965 – Cosmonaut Aleksei Leonov, leaving his spacecraft Voskhod 2 for 12 minutes, becomes the first person to walk in space.
* 1967 – The supertanker Torrey Canyon runs aground off the Cornish coast.
* 1968 – Gold standard: The U.S. Congress repeals the requirement for a gold reserve to back US currency.
* 1969 – The United States begins secretly bombing the Sihanouk Trail in Cambodia, used by communist forces to infiltrate South Vietnam.
* 1970 – Lon Nol ousts Prince Norodom Sihanouk of Cambodia.
* 1971 – In Peru a landslide crashes into Lake Yanahuani, killing 200 at the mining camp of Chungar.
* 1974 – Oil embargo crisis: Most OPEC nations end a five-month oil embargo against the United States, Europe and Japan.
* 1980 – At Plesetsk Cosmodrome in Russia, 50 people are killed by an explosion of a Vostok-2M rocket on its launch pad during a fueling operation.
* 1989 – In Egypt, a 4,400-year-old mummy is found nearby the Pyramid of Cheops.
* 1990 – In the largest art theft in US history, 12 paintings, collectively worth around $300 million, are stolen from the Isabella Stewart Gardner Museum in Boston, Massachusetts.
* 1992 – White South Africans vote overwhelmingly in favour, in a national referendum, to end the racist policy of Apartheid.
* 1994 – Bosnia's Bosniaks and Croats sign the Washington Agreement, ending warring between the Croatian Republic of Herzeg-Bosnia and the Republic of Bosnia and Herzegovina, and establishing the Federation of Bosnia and Herzegovina.
* 1996 – A nightclub fire in Quezon City, Philippines kills 162.
* 1997 – The tail of a Russian Antonov An-24 charter plane breaks off while en-route to Turkey causing the plane to crash and killing all 50 on board and leading to the grounding of all An-24s.
* 2002 – U.S. invasion of Afghanistan: Operation Anaconda ends (started on March 2) after killing 500 Taliban and al Qaeda fighters with 11 allied troop fatalities.
* 2003 – FBI agents raid the corporate headquarters of HealthSouth Corporation in Birmingham, Alabama on suspicion of massive corporate fraud led by the company's top executives.
* 2003 – In the House of Commons, British MPs vote in favour of military intervention in Iraq by 412 votes to 149.
* 2003 – British Sign Language is recognised as an official British language.