The Austro-Hungarian invasion of Bosnia and Herzegovina occurred in 1878 when Austria-Hungary invaded and occupied the Ottoman province of Bosnia Vilayet in accordance with the Congress of Berlin's decision to allow the Austro-Hungarian Army to garrison Bosnia and Herzegovina. An article of the 13 July 1878 Treaty of Berlin granted Austria-Hungary the right to indefinitely occupy and administer the region, while the Ottomans would continue to administer Novi Pazar. The article was meant to prevent the extension of Russian influence in the Balkans and the unification of Serbia and Montenegro, but the Ottomans protested the occupation of Novi Pazar and refused to abide by the treaty. As a result, 82,113 Austro-Hungarian troops was sent to invade the province in late July 1878, facing 40,000 Ottoman Army troops and 53,000 Bosniak militia. The Bosniak Muslims put up fierce resistance, fearing the loss of their privileged status based on their religion. Despite various setbacks, the Austro-Hungarians occupied Sarajevo in October 1878, but only after the deployment of 52 guns and violent street fighting. The fall of Sarajevo led to the Bosniak insurgents retreating into the mountainous countryside, maintaining their resistance around Sarajevo for several weeks. After Hadzi Loja's surrender, the Austro-Hungarians established a new colonial administration. In 1908, in response to the Young Turk Revolution in Anatolia, Austria-Hungary annexed Bosnia and Herzegovina, leading to the Bosnian Crisis.