The First World War (1914-1918)
Serbia and the Austro-Hungarian Empire's conflict:
Austria wanted to extent its empire, and so it did by annexing Bosnia and Herzegovina in 1908. The problem began when Russia and Serbia objected to the annexation.
-Crisis in Bosnia (1908)
Serbia, closely related to Bosnia and Herzegovina geographically and ethnically, demanded that Austria cede a portion of Bosnia and Herzegovina to Serbia. The Austria's threat to invade Serbia if it persisted in their demands eventually made both countries resign to Austria’s action. Although the crisis in Bosnia did not finally lead to war, tensions between both sides increased. The annexation crisis had also repercussions among the other Slav nationalities (Czech, Slovaks, Croats, etc) in the monarchy.
-Conflict with Serbia (1914)
On 28 June 1914, the archduke Franz Ferdinand of Austria and his wife were assassinated by a Serbian nationalist, Gavrilo Princip, in Sarajevo, Bosnia. He belonged to the Serbian secret organization “Black Hand”. The Ministerial Council of the Austro-Hungary Monarchy met on several occasions in order to decide what action the Dual Monarchy should take against the Kingdom of Serbia, finally presenting an ultimatum including several conditions. The rejection of this ultimatum by the Serbians served as a pretext to declare war on Serbia.
Austria-Hungary decided to broke relations with the Kingdom (prevously deteriorated in the Balkan Wars of 1912 and 1913) and prepared for a military invasion in the Balkans, with the support of its powerful ally, Germany. On the other hand, Russia supporting Serbia began its military mobilization towards Austria. Thus, Germany responded to Russia's mobilization by immediately declaring war on France and Russia. This was the trigger for the beginning of the First World War.
Politics
After king Franz-Joseph died in 1916, emperor King Charles I of Austria and IV of Hungary succeeded in the throne. He was the last monarch of the House of Habsburg.
Economy
The four and a half decades between the Austro-Hungarian Compromise of 1867 and the outbreak of World War I, clearly, were a time of rapid expansion in mechanical engineering.
During the First World War, food became a scarce resource in the empire. This could be a key factor of Austria-Hungary’s military, economic and political breakdown. Agricultural production dramatically deteriorated, affecting Austria more than Hungary. The deterioration of agricultural resources affected the livestock as well, especially in Austria where there were declining numbers of cattle, pigs and sheep between 1910 and 1917.