456 – Remistus, Roman general (magister militum), is besieged by a Gothic force at Ravenna and later executed in the Palace in Classis, outside the city.
1111 – Highest Galician nobility led by Pedro Fróilaz de Traba and the bishop Diego Gelmírez crown Alfonso VII as “King of Galicia”.
1176 – The Battle of Myriokephalon is fought between the Byzantine Empire and the Seljuk Turks.
1382 – Louis the Great’s daughter, Mary, is crowned “king” of Hungary.
1462 – The Battle of Świecino (also known as the Battle of Żarnowiec) is fought during Thirteen Years’ War.
1577 – The Treaty of Bergerac is signed between Henry III of France and the Huguenots.
1620 – The Battle of Cecora (1620) is fought between the Ottoman Empire and the Polish–Lithuanian Commonwealth during the Polish–Ottoman War (1620–21).
1630 – The city of Boston, Massachusetts is founded.
1631 – Sweden wins a major victory at the Battle of Breitenfeld against the Holy Roman Empire during the Thirty Years’ War.
1658 – The Battle of Vilanova is fought between the Portugal and Spain during the Portuguese Restoration War.
1683 – Antonie van Leeuwenhoek writes a letter to the Royal Society describing “animalcules”: the first known description of protozoa.
1775 – American Revolutionary War: The Invasion of Canada begins with the Siege of Fort St. Jean.
1776 – The Presidio of San Francisco is founded in New Spain.
1778 – The Treaty of Fort Pitt is signed. It is the first formal treaty between the United States and a Native American tribe (the Lenape or Delaware Indians).
1787 – The United States Constitution is signed in Philadelphia.
1793 – The Battle of Peyrestortes is fought.
1794 – The Battle of Sprimont is fought.
1809 – Peace between Sweden and Russia in the Finnish War; the territory that will become Finland is ceded to Russia by the Treaty of Fredrikshamn.
1814 – Francis Scott Key finishes his poem “Defence of Fort McHenry”, later to be the lyrics of “The Star-Spangled Banner”.
1849 – American abolitionist Harriet Tubman escapes from slavery.
1859 – Joshua A. Norton declares himself “Norton I, Emperor of the United States.”
1861 – Battle of Pavón is fought.
1862 – American Civil War: George B. McClellan halts the northward drive of Robert E. Lee’s Confederate Army in the single-day Battle of Antietam, the bloodiest day in American military history.
1862 – American Civil War: The Allegheny Arsenal explosion results in the single largest civilian disaster during the war.
1894 – Battle of the Yalu River, the largest naval engagement of the First Sino-Japanese War.
1900 – Philippine–American War: Filipinos under Juan Cailles defeat Americans under Colonel Benjamin F. Cheatham Jr. at Mabitac.
1901 – The Battle of Blood River Poort is fought.
1901 – The Battle of Elands River is fought.
1908 – The Wright Flyer flown by Orville Wright, with Lieutenant Thomas Selfridge as passenger, crashes, killing Selfridge, who becomes the first airplane fatality.
1914 – Andrew Fisher becomes Prime Minister of Australia for the third time.
1914 – World War I: The Race to the Sea begins.
1916 – World War I: Manfred von Richthofen (“The Red Baron”), a flying ace of the German Luftstreitkräfte, wins his first aerial combat near Cambrai, France.
1924 – The Border Protection Corps is established in the Second Polish Republic for the defence of the eastern border against armed Soviet raids and local bandits.
1925 – Frida Kahlo suffers near-fatal injuries in a bus accident in Mexico, causing her to abandon her medical studies and take up art
1928 – The Okeechobee hurricane strikes southeastern Florida, killing more than 2,500 people. It is the third deadliest natural disaster in United States history, behind the Galveston hurricane of 1900 and the 1906 San Francisco earthquake.
1930 – The Ararat rebellion is suppressed.
1932 – A speech by Laureano Gómez leads to the escalation of the Leticia Incident.
1939 – World War II: The Soviet Union joins Nazi Germany’s invasion of Poland during the Polish Defensive War of 1939.
1939 – World War II: German submarine U-29 sinks the British aircraft carrier HMS Courageous.
1940 – World War II: Following Nazi Germany’s defeat in the Battle of Britain, Hitler postpones Operation Sea Lion indefinitely.
1941 – World War II: A decree of the Soviet State Committee of Defense, restoring Vsevobuch in the face of the Great Patriotic War, is issued.
1941 – World War II: Soviet forces enter Tehran marking the end of the Anglo-Soviet invasion of Iran.
1944 – World War II: Allied Airborne troops parachute into the Netherlands as the “Market” half of Operation Market Garden.
1944 – World War II: Soviet troops launch the Tallinn Offensive against Germany and pro independence Estonian units.
1944 – World War II: German forces are attacked by the Allies in the Battle of San Marino.
1948 – The Lehi (also known as the Stern gang) assassinates Count Folke Bernadotte, who was appointed by the United Nations to mediate between the Arab nations and Israel.
1948 – The Nizam of Hyderabad surrenders his sovereignty over the Hyderabad State and joins the Indian Union.
1949 – The Canadian steamship SS Noronic burns in Toronto Harbour with the loss of over 118 lives.
1954 – The novel Lord of the Flies by William Golding is first published.
1957 – Malaysia joins the United Nations.
1961 – The world’s first retractable-dome stadium, the Civic Arena, opens in Pittsburgh, Pennsylvania.
1961 –The Minnesota Vikings play and win their first regular season National Football League game.
1965 – The Battle of Chawinda is fought between Pakistan and India.
1974 – Bangladesh, Grenada and Guinea-Bissau join the United Nations.
1976 – The first Space Shuttle, Enterprise, is unveiled by NASA.
1978 – The Camp David Accords are signed by Israel and Egypt.
1980 – After weeks of strikes at the Lenin Shipyard in Gdańsk, Poland, the nationwide independent trade union Solidarity is established.
1980 – Former Nicaraguan President Anastasio Somoza Debayle is killed in Asunción, Paraguay.
1983 – Vanessa Williams becomes the first black Miss America.
1988 – The 1988 Summer Olympics, officially known as the Games of the XXIV Olympiad are opened in Seoul, South Korea.
1991 – Estonia, North Korea, South Korea, Latvia, Lithuania, the Marshall Islands and Micronesia join the United Nations.
1991 – The first version of the Linux kernel (0.01) is released to the Internet.
1992 – An Iranian Kurdish leader and his two joiners are assassinated by political militants in Berlin, Germany.
2001 – The New York Stock Exchange reopens for trading after the September 11 attacks, the longest closure since the Great Depression.
2006 – Fourpeaked Mountain in Alaska erupts, marking the first eruption for the long-dormant volcano in at least 10,000 years.
2006 – An audio tape of a private speech by Hungarian Prime Minister Ferenc Gyurcsány is leaked to the public, in which he confessed that his Hungarian Socialist Party had lied to win the 2006 election, sparking widespread protests across the country.
2011 – Occupy Wall Street movement begins in Zuccotti Park, New York City.
2016 – Two bombs explode in Seaside Park, New Jersey, and Manhattan, New York. 31 people are injured in the Manhattan bombing.