On October 6, 1908, the Dual Monarchy of Austria-Hungary announces its annexation of Bosnia and Herzegovina, dual provinces in the Balkan region of Europe formerly under the control of the Ottoman Empire.
Though Bosnia and Herzegovina were still nominally under the control of the Ottoman Sultan in 1908, Austria-Hungary had administered the provinces since the Congress of Berlin in 1878, when the great powers of Europe awarded the Dual Monarchy the right to occupy the two provinces, with the legal title to remain with Turkey. As the provinces were coveted by many—in fact, both Austria and Hungary wanted Bosnia and Herzegovina for themselves—the decision was more or less a stopgap to preserve the delicate balance of power in Europe. To make matters more complicated, the largely Slavic population of the two provinces had nationalist ambitions of their own, while their fellow Slavs in nearby Serbia yearned to annex them to further their pan-Slavic ambitions.
When rebellion by the Committee of Union and Progress—the so-called Young Turks—took the Ottoman government by storm in 1908, Baron Aloys von Aerenthal, foreign minister of Austria-Hungary, saw his empire’s chance to assert its dominance in the Balkans. Aside from the sultan’s weakness, Russia, the Dual Monarchy’s great rival for power in the Balkans, was also reeling, after a defeat in the Russo-Japanese War and internal revolution in 1905.
The announcement in October 1908 of Austria-Hungary’s annexation of Bosnia and Herzegovina upset the fragile balance of power in the Balkans, enraging Serbia and pan-Slavic nationalists throughout Europe. Though weakened Russia was forced to submit, to its humiliation, its foreign office still viewed Austria-Hungary’s actions as overly aggressive and threatening, despite Aerenthal’s assurances that he did not plan to take Macedonia, another disputed former Ottoman province, next. Russia’s response was to encourage pro-Russian, anti-Austrian sentiment in Serbia and other Balkan provinces, provoking Austrian fears of Slavic expansionism in the region.