On June 28,1914, Archduke Francis Ferdinand, the heir to the throne of Austria-Hungary was assassinated at Sarajevo, Capital of Bosnia by the secret society called ‘Black Hand’ or ‘Union of Death’, formed by die assertive Serbian nationalists whose aim was to unite all Serbians into a single Serbian State. As a result of this assassination, Austria served an ultimatum on Serbia on 23 July making eleven demands and on 28 July, 1914 Austria declared war on Serbia, Russia started preparation for war to support Serbia. On Aug. 1, 1914 Germany declared war on Russia, and on August 3, on France. Germany declared war on France on August 4,1914 and on same day Britain declared war on Germany. Thus the Serajevo crisis triggered World War I in 1914.