It was formed by Josip Broz Tito and the Central Committee of the Communist Party of Yugoslavia on 22 December 1941 in the village of Rudo in Republika Srpska. Initially comprising 1,200 of the best Serb and Montenegrin Partisans under the command of the Spanish Civil War veteran Koča Popović, it began to take on a more multi-ethnic character from March 1942 when 15 Bosniaks from Sarajevo joined the brigade. The formation of the brigade represented a significant change for the Partisans, as it gave the Partisan Supreme Command a politically reliable and mobile force that was not tied to a particular geographic area. This innovation allowed the Partisans to more easily concentrate fighting power at a particular point to achieve a decision, and permitted withdrawal when faced by a superior enemy force. The brigade fought its first battle on the day following its creation, when it encountered Italian troops and the Chetniks as it marched out of Rudo.
