Konstantin "Kosta" Milovanović Pećanac was a Serbian and Yugoslav Chetnik commander (vojvoda) during the Balkan Wars, World War I and World War II. Pećanac fought on the Serbian side in both Balkan Wars and World War I, joining the forces of Kosta Vojinović 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, Pećanac collaborated with both the German military administration and their puppet government in the German-occupied territory of Serbia.

The Chetniks, formally the Chetnik Detachments of the Yugoslav Army, and also the Yugoslav Army in the Homeland and the Ravna Gora Movement, was a Yugoslav royalist and Serbian nationalist movement and guerrilla force in Axis-occupied Yugoslavia. Although it was not a homogeneous movement, it was led by Draža Mihailović. While it was anti-Axis in its long-term goals and engaged in marginal resistance activities for limited periods, it also engaged in tactical or selective collaboration with Axis forces for almost all of the war. The Chetnik movement adopted a policy of collaboration with regard to the Axis, and engaged in cooperation to one degree or another by both establishing a modus vivendi and operating as "legalised" auxiliary forces under Axis control. Over a period of time, and in different parts of the country, the movement was progressively drawn into collaboration agreements: first with the puppet Government of National Salvation in the German-occupied territory of Serbia, then with the Italians in occupied Dalmatia and Montenegro, with some of the Ustaše forces in northern Bosnia, and, after the Italian capitulation in September 1943, with the Germans directly.