World war one By Christian_Symon Jun 28, 1914 The assassination of Archduke Ferdinand The assassination of ArchdukeFerdinand which let to the Austria declaration of war Period: Jun 28, 1914 to Jun 28, 1919 World war one Jul 28, 1914 Austria-Hungary declares war on Serbia. Starts world war one Aug 15, 1914 Schlieffen plan Sep 5, 1914 First Battle of the Marne Dec 9, 1914 Battle of Limanowa Feb 25, 1916 Battle of Verdun Period: Jul 21, 1916 to Sep 11, 1916 Battle of Somme Jan 18, 1917 Unrestricted Submarine Warfare Feb 25, 1917 Second Battle of the Marne Apr 2, 1917 America enters the war Nov 11, 1917 Russian Revolution Nov 11, 1918 Armistice Jun 28, 1919 The Treaty of Versailles