The decision to increase taxes for paying the Ottoman Empire's debts to foreign creditors sparked an outrage in the Balkan provinces, which culminated in the Great Eastern Crisis and ultimately the Russo-Turkish War (1877–78) that provided independence or autonomy for the Christian nations in the empire's Balkan territories, with the subsequent Treaty of Berlin in 1878. The war, however, was disastrous for the already struggling Ottoman economy and the Ottoman Public Debt Administration was established in 1881, which gave the control of the Ottoman state revenues to foreign creditors.[1][16] This made the European creditors bondholders, and assigned special rights to the OPDA for collecting various types of tax and customs revenues.[14] During and after the Serbian–Ottoman War of 1876–78, between 30,000 and 70,000 Muslims, mostly Albanians, were expelled by the Serb army from the Sanjak of Niș and fled to the Kosovo Vilayet.[17][18][19][20][21][22]