League of Communists of Yugoslavia

The League of Communists of Yugoslavia, known until 1952 as the Communist Party of Yugoslavia, was the founding and ruling party of the Socialist Federal Republic of Yugoslavia. It was formed in 1919 as the main communist opposition party in the Kingdom of Serbs, Croats and Slovenes and after its initial successes in the elections, it was proscribed by the royal government and was at times harshly and violently suppressed.

Source: Wikipedia — League of Communists of Yugoslavia (CC BY-SA 4.0)