World War 1 By munderhill18 Jun 28, 1914 Assassination Jul 28, 1914 Austria-Hungary declared war on Serbia Jul 28, 1914 Serbia Aug 1, 1914 Germany Aug 3, 1914 France Aug 4, 1914 Great Britain Aug 4, 1914 Belgium Aug 6, 1914 Russia Oct 28, 1914 Ottoman Empire May 23, 1915 Italy Oct 11, 1915 Bulgaria Mar 9, 1916 Portugal