Konstantin "Kosta" Milovanovic Pecanac (Serbian Cyrillic: ????? ??????????? ???????; 1879–1944) was a Serbian Chetnik commander (vojvoda) during the Balkan Wars, World War I and World War II.
Pecanac fought on the Serbian side in both Balkan Wars and World War I, joining the forces of Kosta Vojinovic during the Toplica uprising of 1917.
Between the wars he was an important leader of Chetnik veteran associations, and was known for his strong hostility to the Yugoslav Communist Party, which made him popular in conservative circles.
As president of the Chetnik Association during the 1930s, he transformed it into an aggressively partisan Serb political organisation with over half a million members.
During World War II, Pecanac collaborated with both the German military administration and their puppet government in the German occupied territory of Serbia.Just before the Axis invasion of Yugoslavia in April 1941, the Yugoslav government provided Pecanac with funds and arms to raise guerrilla units in southern Serbia, Macedonia and Kosovo.
He formed a detachment of about 300 men, mostly in the Toplica river valley in southern Serbia, which avoided destruction during the invasion.
In the first three months after the surrender, Pecanac gathered more troops from Serb refugees fleeing Macedonia and Kosovo.
However, his Chetniks fought only Albanian groups in the region, and did not engage the Germans.
Following the uprising in the occupied territory in early July 1941, Pecanac quickly resolved to abandon resistance against the occupiers, and by the end of August had concluded agreements with the German occupation forces and the puppet government of Milan Nedic to collaborate with them and fight the communist-led Partisans.
In July 1942, rival Chetnik leader Draža Mihailovic arranged for the Yugoslav government-in-exile to denounce Pecanac as a traitor, and his continuing collaboration with the Germans ruined what remained of the reputation he had developed in the Balkan Wars and World War I.
The Germans rapidly realised that Pecanac's Chetniks, whose numbers had grown to 8,000, were inefficient and unreliable, and even the Nedic government had no confidence in them.
They were completely disbanded by March 1943.
Pecanac himself was interned by the Nedic regime for some time, and was killed by agents of Mihailovic in May or June 1944.