How did the creation of Yugoslavia in 1918 affect language policy?

Following the creation of the Kingdom of Serbs, Croats, and Slovenes in 1918, the government implemented language policies designed to foster national unity by downplaying the linguistic differences between Serbian and Croatian. To further this goal of integration, the state championed a joint "Serb-Croatian-Slovene" language, despite the fact that Slovene remained a distinct tongue.1

These efforts were part of a broader push for a centralized, unitary state under the Karadjordjević dynasty, which sought to consolidate power in Belgrade and weaken traditional regional identities. While the government promoted this unified linguistic identity, the practical implementation of these policies was often secondary to the political struggles of the era, and regional differences in legal codes and educational materials persisted in various districts throughout the 1920s.23