The immediate or proximate cause of war was the assassination on NUMBER@1 June NUMBER@2 of Archduke PERSON@1 of LOCATION@1 , heir to the MISC@1 throne , by PERSON@2 , a MISC@2 nationalist .

Causes On June NUMBER@1 , NUMBER@2 , Archduke PERSON@1 , who was heir to the throne in LOCATION@2 , visited LOCATION@3 with his wife .
