

The German war plan called for the swiftest possible capture of Paris, hoping to knock France out of the war before Russia could fully mobilize its large but low-tech military. But the literal timing shouldn't confuse you - it had long been French policy to support Serbia against Austria in hopes of initiating a war in which Russia would help France fight Germany, which was far too powerful for France to fight alone. The violation of Belgian neutrality brought Britain into the war and it was off to the races.

Thus the main practical step Germany took to defend Austria was to launch a preemptive attack on France and Belgium, neither of whom had officially entered the war yet. German war planning assumed that any war with Russia would expand to include war with France, and the operational plan called for attacking France first. This required Germany to go to war in defense of its ally. Then Russia declared war on Austria-Hungary. First Austria-Hungary declared war on Serbia after Serbia refused to acceed to Vienna's extensive demands regarding Serbian support for anti-Austrian groups. The main participants in the war mobilized over the course of about a week. By chance, Gavrilo Princip had by this time moved over to Franz Joseph Street and he was able to take the fatal shot. Franz Ferdinand ordered his car to turn around so he could visit people injured by the grenade but his driver misunderstood, and continued on the original route where, while attempting to turn around, his car stalled. The assassins believed their plot had failed. The motorcade then continued past the other assassins, none of whom acted as they lacked clear shots in the commotion. The second assassin tossed a grenade that injured several people. The first assassin was standing near a policeman and didn't use his weapon. He was joined in the city by seven Serbian terrorists there to kill him, in hopes of removing a prominent moderate from the line of succession and heightening the tensions between Vienna and its South Slavic subjects.

Austro-Hungarian Archduke Franz Ferdinand arrived in Sarajevo, then part of the Habsburg dominion, on June 28, 1914.
