September 9

337 – Constantine II, Constantius II, and Constans succeed their father Constantine I as co-emperors. The Roman Empire is divided between the three Augusti. 1000 – Battle of Svolder, Viking Age. 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. 1493 – Christopher Columbus, with 17 ships and 1,200 men, sails on second voyage from Cadiz. 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. 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. 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. 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. 1801 – Alexander I of Russia confirms the privileges of Baltic provinces. 1839 – John Herschel takes the first glass plate photograph.