14 – Agrippa Postumus, adopted son of the late Roman emperor Augustus, is executed by his guards while in exile under mysterious circumstances.
636 – Battle of Yarmouk: Arab forces led by Khalid ibn al-Walid take control of Syria and Palestine away from the Byzantine Empire, marking the first great wave of Muslim conquests and the rapid advance of Islam outside Arabia.
917 – Battle of Acheloos: Tsar Simeon I of Bulgaria decisively defeats a Byzantine army.
1000 – The foundation of the Hungarian state by Saint Stephen, celebrated as a National Day in Hungary.
1083 – Canonization of the first King of Hungary, Saint Stephen and his son Saint Emeric.
1308 – Pope Clement V pardons Jacques de Molay, the last Grand Master of the Knights Templar, absolving him of charges of heresy.
1391 – Konrad von Wallenrode becomes the 24th Hochmeister of the Teutonic Order.
1467 – The Second Battle of Olmedo takes places as part of a succession conflict between Henry IV of Castile and his half-brother Alfonso, Prince of Asturias.
1519 – Philosopher and general Wang Yangming defeats Zhu Chenhao, ending the Prince of Ning rebellion against the reign of the Ming Dynasty emperor Zhengde.
1672 – Former Grand Pensionary Johan de Witt and his brother Cornelis are brutally murdered by an angry mob in The Hague.
1707 – The first Siege of Pensacola comes to end with the failure of the British to capture Pensacola, Florida.
1710 – War of the Spanish Succession: A multinational army led by the Austrian commander Guido Starhemberg defeats the Spanish-Bourbon army commanded by Alexandre Maître, Marquis de Bay in the Battle of Saragossa.
1775 – The Spanish establish the Presidio San Augustin del Tucson in the town that became Tucson, Arizona.
1794 – Battle of Fallen Timbers: American troops force a confederacy of Shawnee, Mingo, Delaware, Wyandot, Miami, Ottawa, Chippewa, and Potawatomi warriors into a disorganized retreat.
1858 – Charles Darwin first publishes his theory of evolution through natural selection in The Journal of the Proceedings of the Linnean Society of London, alongside Alfred Russel Wallace's same theory.
1866 – President Andrew Johnson formally declares the American Civil War over.
1882 – Tchaikovsky's 1812 Overture debuts in Moscow, Russia.
1910 – The Great Fire of 1910 (also commonly referred to as the "Big Blowup" or the "Big Burn") occurs in northeast Washington, northern Idaho (the panhandle), and western Montana, burning approximately 3 million acres (12,000 km2).
1914 – World War I: German forces occupy Brussels.
1920 – The first commercial radio station, 8MK (now WWJ), begins operations in Detroit, Michigan.
1926 – Japan's public broadcasting company, Nippon Hōsō Kyōkai (NHK) is established.
1938 – Lou Gehrig hits his 23rd career grand slam, a record that stood for 75 years until it was broken by Alex Rodriguez.
1940 – In Mexico City, Mexico exiled Russian revolutionary Leon Trotsky is fatally wounded with an ice axe by Ramón Mercader. He dies the next day.
1940 – World War II: British Prime Minister Winston Churchill makes the fourth of his famous wartime speeches, containing the line "Never was so much owed by so many to so few".
1944 – World War II: 168 captured allied airmen, including Phil Lamason, accused by the Gestapo of being "terror fliers", arrive at Buchenwald concentration camp.
1944 – World War II: The Battle of Romania begins with a major Soviet Union offensive.
1950 – Korean War: United Nations repel an offensive by North Korean divisions attempting to cross the Naktong River and assault the city of Taegu.
1955 – In Morocco, a force of Berbers from the Atlas Mountains region of Algeria raid two rural settlements and kill 77 French nationals.
1960 – Senegal breaks from the Mali Federation, declaring its independence.
1962 – The NS Savannah, the world's first nuclear-powered civilian ship, embarks on its maiden voyage.
1968 – Soviet Union-dominated Warsaw Pact troops invade Czechoslovakia, crushing the Prague Spring.
1975 – Viking Program: NASA launches the Viking 1 planetary probe toward Mars.
1977 – Voyager Program: NASA launches the Voyager 2 spacecraft.
1986 – In Edmond, Oklahoma, U.S. Postal employee Patrick Sherrill guns down 14 of his co-workers and then commits suicide.
1988 – "Black Saturday" of the Yellowstone fire in Yellowstone National Park
1988 – Peru becomes a member of the Berne Convention copyright treaty.
1988 – Iran–Iraq War: A ceasefire is agreed after almost eight years of war.
1988 – The Troubles: Eight British soldiers are killed and 28 wounded when their bus is hit by an IRA roadside bomb in Ballygawley, County Tyrone.
1989 – The pleasure boat Marchioness sinks on the River Thames following a collision. Fifty-one people are killed.
1989 – The O-Bahn Busway in Adelaide, the world's longest guided busway, opens.
1991 – Dissolution of the Soviet Union, August Coup: More than 100,000 people rally outside the Soviet Union's parliament building protesting the coup aiming to depose President Mikhail Gorbachev.
1991 – Estonia, annexed by the Soviet Union in 1940, issues a decision on the re-establishment of independence on the basis of historical continuity of its pre-World War II statehood.
1993 – After rounds of secret negotiations in Norway, the Oslo Accords are signed, followed by a public ceremony in Washington, D.C. the following month.
1997 – Souhane massacre in Algeria; over 60 people are killed and 15 kidnapped.
1998 – The Supreme Court of Canada rules that Quebec cannot legally secede from Canada without the federal government's approval.
1998 – U.S. embassy bombings: The United States launches cruise missile attacks against alleged al-Qaeda camps in Afghanistan and a suspected chemical plant in Sudan in retaliation for the August 7 bombings of American embassies in Kenya and Tanzania.
2002 – A group of Iraqis opposed to the regime of Saddam Hussein take over the Iraqi Embassy in Berlin, Germany for five hours before releasing their hostages and surrendering.
2008 – Spanair Flight 5022, from Madrid, Spain to Gran Canaria, skids off the runway and crashes at Barajas Airport. One hundred forty-six people are killed in the crash, and eight more die later. Only 18 people survive.
2012 – A prison riot in the Venezuelan capital, Caracas, kills at least 20 people.
2014 – 72 people are killed in Japan's Hiroshima prefecture by a series of landslides caused by a month's worth of rain that fell in one day.