the region was the site of a rebellion of the local serbian population against bulgarian occupational forces in 1917 during world war i. the toplica rebellion (serbian: toplički ustanak/топлички устанак) broke out because of the many atrocities of the bulgarian army (mass slaughters, pillage and burning of the houses and forceful drafting of the serbian population into the bulgarian army). initially, under the leadership of kosta vojinoviċ (1890-1917), rebels had some success, liberating many places in the area (at that time, "niški okrug"). all three occupying forces in serbia, austro-hungary, germany and bulgaria, joined forces and brought three artillery divisions into the area, crushing the rebellion (several thousand killed, mostly civilians).