41 – Claudius is proclaimed Roman emperor by the Praetorian Guard after they assassinate the previous emperor, his nephew Caligula. 914 – Start of the First Fatimid invasion of Egypt. 1438 – The Council of Basel suspends Pope Eugene IV. 1458 – Matthias Corvinus is elected King of Hungary. 1536 – King Henry VIII of England suffers an accident while jousting, leading to a brain injury that historians say may have influenced his later erratic behaviour and possible impotence. 1651 – Arauco War: Spanish and Mapuche authorities meet in the Parliament of Boroa renewing the fragile peace established at the parliaments of Quillín in 1641 and 1647. 1679 – King Charles II of England dissolves the Cavalier Parliament. 1742 – Charles VII Albert becomes Holy Roman Emperor. 1758 – During the Seven Years' War the leading burghers of Königsberg submit to Elizabeth of Russia, thus forming Russian Prussia (until 1763). 1817 – Crossing of the Andes: Many soldiers of Juan Gregorio de las Heras are captured during the action of Picheuta. 1835 – Slaves in Salvador da Bahia, Brazil, stage a revolt, which is instrumental in ending slavery there 50 years later. 1848 – California Gold Rush: James W. Marshall finds gold at Sutter's Mill near Sacramento. 1857 – The University of Calcutta is formally founded as the first fully fledged university in South Asia. 1859 – The United Principalities of Moldavia and Wallachia (later named Romania) is formed as a personal union under the rule of Domnitor Alexandru Ioan Cuza. 1900 – Second Boer War: Boers stop a British attempt to break the Siege of Ladysmith in the Battle of Spion Kop. 1908 – The first Boy Scout troop is organized in England by Robert Baden-Powell. 1915 – World War I: British Grand Fleet battle cruisers under Vice-Admiral Sir David Beatty engage Rear-Admiral Franz von Hipper's battle cruisers in the Battle of Dogger Bank. 1916 – In Brushaber v. Union Pacific Railroad Co., the Supreme Court of the United States declares the federal income tax constitutional.