World War 1 By facebooker_100004610914145 Jun 6, 1914 Archduke Ferdinand and his wife are assassinated by a Serbian Jul 28, 1914 Austria-Hungary declares war on Serbia. Jul 30, 1914 Russia mobilizes Aug 1, 1914 Germany declares war on Russia Aug 3, 1914 Germany declares war on France Aug 4, 1914 Britain declares war on Germany Aug 6, 1914 Austria-Hungary declares war on Russia Aug 12, 1914 France and Britain declare war on Austria-Hungary. Apr 6, 1917 USA entered the war. Nov 11, 1918 Date of Armistice Jun 28, 1919 The date of Treaty of Versailles