The assassin was Gavrilo Princip of the Serbian society
The Black Hand, a terrorist organization. The Serbian
government was cognizant of the plot; the world
generally was outraged.
July 23. Austrian ultimatum to Belgrade (48 hours).
July 28. AUSTRIA DECLARED WAR ON SERBIA.
Belgrade was bombarded the next day, though Austria
was not ready for real operations until about August 12.
The declaration of war was meant to create a fait
July 29. The Russian tsar agreed to general mobilization.
July 31. Germany proclaimed "state of threatening
danger of war."
Sent a 12-hour ultimatum to Russia demanding
cessation of preparations on the German frontier.
Germany refused a British request that the neutrality of
Belgium be respected.