September 9 is the 252nd day of the year (253rd in leap years) in the Gregorian calendar; 113 days remain until the end of the year.
Events Pre-1600
337 – Constantine II, Constantius II, and Constans succeed their father Constantine I as coemperors. The Roman Empire is divided between the three Augusti.[1][2] 1000 – Battle of Svolder during the Viking Age.[3] 1141 – Yelü Dashi, the Liao dynasty general who founded the Qara Khitai, defeats the Seljuq and Kara-Khanid forces at the Battle of Qatwan.
1320 – In the Battle of Saint George, the Byzantines under Andronikos Asen ambush and defeat the forces of the Principality of Achaea, securing possession of Arcadia.
1488 – Anne becomes sovereign Duchess of Brittany, becoming a central figure in the struggle for influence that leads to the union of Brittany and France.
1493 – Battle of Krbava Field, a decisive defeat of Croats in Croatian struggle against the invasion by the Ottoman Empire.[4] 1493 – Christopher Columbus, with 17 ships and 1,200 men, sails on second voyage from Cadiz.[5] 1499 – The citizens of Lisbon celebrate the triumphal return of the explorer Vasco de Gama, completing his two-year journey around the Cape of Good Hope to India.[6] 1513 – James IV of Scotland is defeated and dies in the Battle of Flodden, ending Scotland's involvement in the War of the League of Cambrai.[7] 1543 – Mary Stuart, at nine months old, is crowned 'Queen of Scots' in the central Scottish town of Stirling.
1561 – The ultimately unsuccessful Colloquy of Poissy opens in an effort to reconcile French Catholics and Protestants.
1588 – Thomas Cavendish in his ship Desire enters Plymouth and completes the first deliberately planned voyage of circumnavigation.[ 8] 1601–1900
1739 – Stono Rebellion, the largest slave uprising in Britain's mainland North American colonies prior to the American Revolution, erupts near Charleston, South Carolina.
1776 – The Continental Congress officially names its union of states the United States.
1791 – Washington, D.C., the capital of the United States, is named after President George Washington.
1796 – Grenelle camp affair, a failed uprising by supporters of Gracchus Babeuf against the French Directory[9] 1801 – Alexander I of Russia confirms the privileges of Baltic provinces.
1839 – John Herschel takes the first glass plate photograph.[10] 1845 – Possible start of the Great Famine of Ireland.[11][12] 1850 – The Compromise of 1850 transfers a third of Texas's claimed territory to federal control in return for the U.S. federal government assuming $10 million of Texas's pre-annexation debt.
1850 – California is admitted as the thirty-first U.S. state.
1855 – Crimean War: The Siege of Sevastopol comes to an end when Russian forces abandon the city.
1863 – American Civil War: The Union Army enters Chattanooga, Tennessee.
1888 – A British force repels an Egyptian force led by Ahmed Urabi in the battle of Qassasin during the Anglo-Egyptian War.[13] 1892 – Amalthea becomes the last moon to be discovered without the use of photography.
1901–present 1914 – World War I: The creation of the Canadian Automobile Machine Gun Brigade, the first fully mechanized unit in the British Army.
1922 – The Greco-Turkish War effectively ends with Turkish victory over the Greeks in Smyrna.
1923 – Mustafa Kemal Atatürk, the founder of the Republic of Turkey, founds the Republican People's Party.
1924 – Hanapepe massacre occurs on Kauai, Hawaii.
1926 – Yleisradio (YLE), the Finnish national public broadcasting company, begins its broadcasts.[14] 1936 – The crews of Portuguese Navy frigate NRP Afonso de Albuquerque and destroyer Dão mutinied against the Salazar dictatorship's support of General Franco's coup and declared their solidarity with the Spanish Republic.
1939 – World War II: The Battle of Hel begins, the longest-defended pocket of Polish Army resistance during the German invasion of Poland.
1939 – Burmese national hero U Ottama dies in prison after a hunger strike to protest Britain's colonial government.
1940 – George Stibitz pioneers the first remote operation of a computer.
1940 – Treznea Massacre in Transylvania. 1942 – World War II: A Japanese floatplane drops incendiary bombs on Oregon.
1943 – World War II: The Allies land at Salerno and Taranto, Italy.
1944 – World War II: The Fatherland Front takes power in Bulgaria through a military coup in the capital and armed rebellion in the country. A new pro-Soviet government is established.
1945 – Second Sino-Japanese War: The Empire of Japan formally surrenders to China.
1947 – First case of a computer bug being found: A moth lodges in a relay of a Harvard Mark II computer at Harvard University.