1) Austria
had been determined to capture Balkan region.
2) For
this reason, there was a conflict between Austria and Serbia over Bosnia and
Herzegovina.
3) Austria
annexed Bosnia and Herzegovina which created great unrest and grievance over
Balkan region.
4) Royal
representative of Austria, Prince Archduke Ferdinand was assassinated at
Sarajevo, Bosnian capital by an extremist Serbian citizen.
5) In
retaliation, Austria imposed unacceptable demands on Serbia which were to be
fulfilled within 48 hours.
6) Russia
supported Serbia and with her support, emboldened Serbia refused to accept the
demand of Austria.
As
a result Austria declared war on Serbia on 28th July 1914