The Fiume Crisis refers to a conflict that arose in the early 20th century over the city of Fiume, located on the Adriatic Sea. After World War I, the city was claimed by both Italy and the newly formed Kingdom of Serbs, Croats, and Slovenes. Tensions escalated when Italian nationalist poet Gabriele D'Annunzio led a group of armed men to occupy Fiume in 1919, asserting Italian claims to the territory. The crisis highlighted the complexities of national identity and territorial disputes in the post-war period. In 1920, the Treaty of Rapallo attempted to resolve the issue by establishing Fiume as an independent state, but this arrangement was short-lived. Eventually, in 1924, Fiume was officially annexed by Italy, ending the crisis.