Petar "Peko" Dapčević was a Yugoslav communist who fought as a volunteer in the Spanish Civil War, joined the Partisan uprising in Montenegro, and became commander of the Yugoslav 1st Proletarian Corps, 1st and 4th Armies.

The Yugoslav volunteers in the Spanish Civil War, known as Spanish fighters and Yugoslav brigadistas, was a contingent of volunteers from the Kingdom of Yugoslavia that fought for the Republicans during the Spanish Civil War (1936–1939). An estimated 1,664 "Yugoslav brigadistas" fought in the war, out of whom c. 800 were killed in action. According to Spanish statistics, 148 Yugoslav volunteers received the officer rank during the conflict.