In the aftermath of World War I, European borders and political alliances were undergoing considerable transformation. The Treaty of Rapallo, signed on November 12, 1920, aimed to address some of these changes between Italy and the newly formed Kingdom of Serbs, Croats, and Slovenes. The kingdom emerged from the remnants of the Austro-Hungarian Empire, and its leadership was keen to establish itself on the international stage. Italy, on the other hand, sought to expand its influence in the Adriatic region.

The negotiations took place in Rapallo, a small coastal town in Italy, which became the backdrop for diplomatic discussions. Key issues included the fate of Fiume, a port city that was hotly disputed between the two nations. While the treaty stipulated mutual recognition and outlined provisions for cooperation, it did not definitively resolve the status of Fiume, leading to future tensions. Nonetheless, the agreement represented an important step toward stable relations in a post-war Europe fraught with ethnic and nationalistic tensions.

Ultimately, the Treaty of Rapallo was one of the early diplomatic efforts to prevent further conflict in the region, setting the stage for subsequent agreements. However, the unresolved territorial claims continued to create a complex and often volatile political landscape in the Balkans and Adriatic until the onset of World War II.