In accordance with the Treaty of Rome, Fiume becomes annexed as part of Italy.

The Treaty of Rome was agreed on 27 January 1924, when Italy and the Kingdom of Serbs, Croats and Slovenes agreed that Fiume would be annexed to Italy as the Province of Fiume, and the town of Sušak would be part of the Kingdom of Serbs, Croats and Slovenes.

Rijeka is the principal seaport and the third-largest city in Croatia. It is located in Primorje-Gorski Kotar County on Kvarner Bay, an inlet of the Adriatic Sea and in 2021 had a population of 107,964 inhabitants. Historically, because of its strategic position and its excellent deep-water port, the city was fiercely contested, especially between the Holy Roman Empire, Venice, Italy and Yugoslavia, changing rulers and demographics many times over centuries. According to the 2021 census data, 85% of its citizens are Croats, along with small numbers of Serbs, Bosniaks and Italians.