During 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.[5][6][7][8][9][6] Within the context of the Serbian–Ottoman War, the Ottoman Sultan Abdul Hamid II unleashed his auxiliary troops consisting of Kosovar Albanians on the remaining Serbs before and after the Ottoman army's retreat in 1878.[10] Tensions in the form of revenge attacks arose by incoming Albanian refugees on local Kosovo Serbs that contributed to the beginnings of the ongoing Serbian-Albanian conflict in coming decades.[2][3][4]