What is April 9?
{{calendar}} {{day}} == Events == === Up to 1900 === *[[193]] &ndash; [[Septimius Severus]] is proclaimed [[Roman Emperor]] by the [[army]] in Illyricum. *[[1241]] &ndash; [[Battle of Liegnitz]]: [[Mongol Empire]] forces defeat the German and Polish armies. *[[1388]] &ndash; Despite being outnumbered 16 to 1, forces of the [[Switzerland|Old Swiss Confederacy]] are victorious over the [[Archduchy of Austria]] in the [[Battle of Nafels]]. *[[1413]] &ndash; King [[Henry V of England]] is crowned. *[[1440]] &ndash; [[Christopher of Bavaria]] is appointed [[King]] of [[Denmark]]. *[[1454]] &ndash; The [[Treaty of Lodi]] is signed, establishing a balance of power among the northern [[Italy|Italian]] [[city]] [[states]] for almost 50 years. *[[1511]] &ndash; [[Saint John's College]], [[Cambridge]], receives its charter. *[[1609]] &ndash; [[Eighty Years' War]]: [[Spain]] and the [[Netherlands|Dutch Republic]] sign the [[Treaty of Antwerp]]. *[[1682]] &ndash; [[Robert Cavelier de La Salle]] discovers the mouth of the [[Mississippi River]]. *[[1860]] &ndash; On his [[phonautograph]] [[machine]], [[Edouard-Leon Scott de Martinville]] makes the oldest–known recording of an [[Hearing|audible]] [[human]] [[voice]]. *[[1865]] &ndash; The [[American Civil War]] ends, as [[Confederate States of America|Confederate]] general [[Robert E. Lee]] surrenders to [[Ulysses S. Grant]] at [[Appomattox]] Courthouse in [[Virginia]]. *[[1867]] &ndash; By a single vote, the [[United States]] Senate approves the treaty with [[Russia]] for the purchase of [[Russian America]], present–day [[Alaska]]. === 1901 &ndash; 2000 === *[[1914]] &ndash; [[Mexican Revolution]]: One of the world's first naval/air skirmishes takes place off the coast of western [[Mexico]]. *[[1916]] &ndash; [[World War I]]: [[Battle of Verdun]] – German forces launch their third offensive of the [[battle]]. *[[1917]] &ndash; [[World War I]]: [[Battle of Arras (1917)|Battle of Arras]] – The battle begins when [[Canada|Canadian]] [[corps]] execute a massive assault on the Vi