The first communist groups in Zagreb based on the principles of the Russian Bolsheviks were formed already in December. During this time, Ćopić collaborated with left-wing artists August Cesarec and Miroslav Krleža, as well as later leading party members Simo Miljuš and Đuro Cvijić. Members of the group dispersed to their hometowns to form chapters throughout the region.
The initial communist organizations in Zagreb based on Bolshevik ideology were established by December. During this time, Ćopić collaborated with left-wing artists Cesarec and Krleža, along with future party leaders Miljuš and Cvijić. Members of the group dispersed to their hometowns to establish chapters throughout the region.