The Treaty of Rapallo was a 1920 treaty between Italy and the Kingdom of Serbs, Croats and Slovenes (later kingdom of Yugoslavia), issued to solve the dispute over some territories in current Slovenia and Croatia.
Tension between the kingdoms of Italy and Yugoslavia arose at the end of World War I, when Austria-Hungary Empire dissolved.
According to the treaty, Zara/Zadar was annexed to Italy, while Rijeka/Fiume was to become an independent city, thus ending Gabriele d'Annunzio adventure.
The treaty was completed in 1924, when Italy and Yugoslavia signed the treaty of Rome, which gave Fiume to Italy and Soca to Yugoslavia.