Serbia
Franz Ferdinand
Serbia
Austria-Hungary on Serbia.
The 1st country to declare war on Serbia was Austria-Hungary.
austria declared war on Serbia in 1914
Serbia
an act of terrorism
it caused Serbia to declare war on Austria Hungary
it caused Serbia to declare war on austria hungary
July 28, 1914
The assassination of Austrian Archduke Ferdinand was the immediate cause of World War I. He was killed by a Serbian terrorist, which caused Austria to declare war on Serbia. Serbia was allied with Russia, who intervened, causing Germany to declare war on Russia, which caused France to declare war on Germany.