On this Day, in 1914: World War I broke out when Austria-Hungary declared war on Serbia

On July 28, 1914, one month after the assassination Archduke Franz Ferdinand in Sarajevo, Austria-Hungary declared war on Serbia, igniting the Great War which saw the collapse of empires and the rise of nations.

The assassination of the heir to the Austro-Hungarian throne, Archduke Franz Ferdinand, by Bosnian Serb nationalists in the Bosnian capital Sarajevo at the end of June 1914 began a month of diplomatic manoeuvring between Austria-Hungary, Germany, Russia, France and Great Britain, known as the July Crisis.

The July Crisis and World War I

Franz Ferdinand’s assassin, Gavrilo Princip, was arrested and interrogated by police and military authorities. But, while he and his collaborators testified that they had acted independently and without the knowledge or assistance of the Serbian government, many in Austria-Hungary believed that Serbia and its leaders had been involved in the assassination plot.

Serbia had indeed been a threat and irritant to Austria-Hungary, particularly since it had emerged victorious from the recent Balkan Wars, and while few mourned Franz Ferdinand himself, militarists in the Austro-Hungarian imperial government saw the incident as an opportunity to invade Serbia and crush its rebellious elements.

But, wary of the reaction of the Russian Empire, who was a major supporter of Serbia, Austria-Hungary first sought a guarantee from its own ally Germany. And on July 5, Kaiser Wilhelm II, fearing Russia’s growing economic power, issued his famous ‘blank cheque’ telling Vienna that it could proceed as it wished, and that Germany would back them if Russia intervened.

Understanding the Austro-Hungarian grievance against Serbia to be a pretext orchestrated by Germany, Russia also decided that it needed to show strength by protecting its Serbian ally and in turn declared that it would intervene if war was to break out between Austria-Hungary and Serbia.

The rise of nations in Central Europe

And on July 23, Austria-Hungary delivered a series of ten demands that were made intentionally unacceptable to Serbia in an effort to provoke a war. As expected, Serbia accepted all the terms of the ultimatum except for article six, which demanded that Austrian delegates be allowed in Serbia for the purpose of participation in the investigation into the Archduke’s assassination.

Austria-Hungary immediatly broke off diplomatic relations with Serbia, the two countries ordered a general mobilisation, and on July 28, a month after the assassination, Austria-Hungary declared war on Serbia. The following day, the first shots of World War I were fired by the Austrian monitor SMS Bodrog, which bombarded Belgrade.

Aware that it would have to act together with its Russian ally to defeat its German rival, France escalated its preparations. And after repeatedly offering to mediate, Great Britain aligned with Russia and France. The network of interlocking alliances quickly enlarged the crisis from a bilateral issue in the Balkans to one involving most of Europe. By early August, the dispute between Serbia and Austria-Hungary had already become a sidenote to the general European war.

World War I was a significant turning point in the political, cultural, economic and social climate of the world, sparking numerous revolutions and uprisings: the Austro-Hungarian, German and Russian Empires ceased to exist, and numerous new states were created from their remains, including Poland, Czechoslovakia and Hungary.

Find out more about Central European history in our On this Day series.

On this Day, in 1918: the personal union between Austria and Hungary was dissolved