* 404 BC – Peloponnesian War: Lysander's Spartan Armies defeated the Athenians and the war ends.
* 1134 – The name Zagreb was mentioned for the first time in the Felician Charter relating to the establishment of the Zagreb Bishopric around 1094.
* 1607 – Eighty Years' War: The Dutch fleet destroys the anchored Spanish fleet at Gibraltar.
* 1644 – The Chongzhen Emperor, the last Emperor of Ming Dynasty China, commits suicide during a peasant rebellion led by Li Zicheng.
* 1707 – The Habsburg army is defeated by Bourbon army at Almansa (Spain) in the War of the Spanish Succession.
* 1792 – Highwayman Nicolas J. Pelletier becomes the first person executed by guillotine.
* 1792 – La Marseillaise (the French national anthem) is composed by Claude Joseph Rouget de Lisle.
* 1804 – The western Georgian kingdom of Imereti accepts the suzerainty of the Russian Empire
* 1829 – Charles Fremantle arrives in HMS Challenger off the coast of modern-day Western Australia prior to declaring the Swan River Colony for the United Kingdom.
* 1846 – Thornton Affair: Open conflict begins over the disputed border of Texas, triggering the Mexican-American War.
* 1847 – The last survivors of the Donner Party are out of the wilderness.
* 1849 – The Governor General of Canada, Lord Elgin, signs the Rebellion Losses Bill, outraging Montreal's English population and triggering the Montreal Riots.
* 1859 – British and French engineers break ground for the Suez Canal.
* 1861 – American Civil War: The Union Army arrives in Washington, D.C.
* 1862 – American Civil War: Forces under Union Admiral David Farragut demand the surrender of the Confederate city of New Orleans, Louisiana.
* 1864 – American Civil War: The Battle of Marks' Mills.
* 1898 – Spanish-American War: The United States declares war on Spain.
* 1901 – New York becomes the first U.S. state to require automobile license plates.
* 1915 – World War I: The Battle of Gallipoli begins—The invasion of the Turkish Gallipoli Peninsula by Australian, British, French and New Zealand troops begins with landings at Anzac Cove and Cape Helles.
* 1916 – Easter Rebellion: The United Kingdom declares martial law in Ireland.
* 1916 – Anzac Day is commemorated for the first time on the first anniversary of the landing at Anzac Cove.
* 1920 – At the San Remo conference, the principal Allied Powers of World War I adopt a resolution to determine the allocation of Class "A" League of Nations mandates for administration of the former Ottoman-ruled lands of the Middle East.
* 1938 – U.S. Supreme Court delivers its opinion in Erie Railroad Co. v. Tompkins and overturns a century of federal common law.
* 1939 – DC Comics publishes its second major superhero in Detective Comics #27; he is Batman, one of the most popular comic book superheroes of all time.
* 1943 – The Demyansk Shield for German troops in commemoration of Demyansk Pocket is instituted.
* 1944 – The United Negro College Fund is incorporated.
* 1945 – Elbe Day: United States and Soviet troops meet in Torgau along the River Elbe, cutting the Wehrmacht of Nazi Germany in two, a milestone in the approaching end of World War II in Europe.
* 1945 – The Nazi occupation army surrenders and leaves Northern Italy after a general partisan insurrection by the Italian resistance movement; the puppet fascist regime dissolves and Benito Mussolini tries to escape. This day is taken as symbolic of the Liberation of Italy.
* 1945 – Fifty nations gather in San Francisco, California to begin the United Nations Conference on International Organizations.
* 1945 – The last German troops retreat from Finland's soil in Lapland, ending the Lapland War. Military acts of Second World War end in Finland.
* 1953 – Francis Crick and James D. Watson publish Molecular structure of nucleic acids: a structure for deoxyribose nucleic acid describing the double helix structure of DNA.
* 1959 – The St. Lawrence Seaway, linking the North American Great Lakes and the Atlantic Ocean, officially opens to shipping.
* 1960 – The U.S. Navy submarine USS Triton completes the first submerged circumnavigation of the globe.
* 1961 – Robert Noyce is granted a patent for an integrated circuit.
* 1965 – Teenage sniper Michael Andrew Clark kills three and wounds six others shooting from a hilltop along Highway 101 just south of Santa Maria, California.
* 1966 – The city of Tashkent is destroyed by a huge earthquake.
* 1972 – Vietnam War: Nguyen Hue Offensive – The North Vietnamese 320th Division forces 5,000 South Vietnamese troops to retreat and traps about 2,500 others northwest of Kontum.
* 1974 – Carnation Revolution: A leftist military coup in Portugal overthrows the Estado Novo regime and eventually establishes a democratic government.
* 1975 – As North Vietnamese forces close in on the South Vietnamese capital Saigon, the Australian Embassy is closed and evacuated, almost ten years to the day since the first Australian troop commitment to South Vietnam.
* 1981 – More than 100 workers are exposed to radiation during repairs of a nuclear power plant in Tsuruga, Japan.
* 1982 – Israel completes its withdrawal from the Sinai peninsula per the Camp David Accords.
* 1983 – American schoolgirl Samantha Smith is invited to visit the Soviet Union by its leader Yuri Andropov after he read her letter in which she expressed fears about nuclear war.
* 1983 – Pioneer 10 travels beyond Pluto's orbit.
* 1986 – Mswati III is crowned King of Swaziland, succeeding his father Sobhuza II.
* 1988 – In Israel, John Demjanuk is sentenced to death for war crimes committed in World War II.
* 2003 – The Human Genome Project comes to an end two and a half years earlier than expected.
* 2005 – The final piece of the Obelisk of Axum is returned to Ethiopia after being stolen by the invading Italian army in 1937.
* 2005 – Bulgaria and Romania sign accession treaties to join the European Union.
* 2005 – 107 die in Amagasaki rail crash in Japan.
* 2007 – Boris Yeltsin's funeral – the first to be sanctioned by the Russian Orthodox Church for a head of state since the funeral of Emperor Alexander III in 1894.
* 2011 – At least 300 people killed in deadliest tornado outbreak in the Southern United States since the 1974 Super Outbreak.