It was the only uprising in an occupied country during the entire First World War; Serbian sources claim that as many as 20,000 Serbs died in the revolt and its aftermath.
However, rather than surrendering and capitulating, the Serbian military and political leaders decided on a long and arduous army retreat south towards Albania, hoping to reach the Adriatic coast for evacuation and regrouping.
[3] Romania entering the war in August 1916 awakened hope in the Serbian population of a breakthrough of the Salonika front, some arming themselves and taking to the forests.
[3] Kosta Vojinović began the organization of resistance, and in the summer of 1916, established a band in Leposavić, the core of the future Ibar–Kopaonik Detachment.
[3] At the end of September 1916, the Serbian High Command sent Kosta Pećanac, reserve infantry lieutenant and veteran Chetnik Vojvoda, by airplane into Toplica.
He was tasked to establish a secret resistance organization to be activated when the Allies and the Serbian Army were to break the Salonika front and arrive at Skoplje.
[3] The peak of Serbian discontent came with the Bulgarian announcement of conscription of local Serbs aged 18–50 for military service.
[5] On 12 March, the Bulgarian counter-attack started under the command of Alexander Protogerov involving IMRO forces led by Tane Nikolov.