A city of western Croatia on the Adriatic Sea west-southwest of Zagreb. Held at various times by Austria, Croatia, France, and Hungary, it was seized by Italian irregulars in 1919. The Treaty of Rapallo between Italy and Yugoslavia (1920) guaranteed its status as an independent city, although it was formally annexed by Italy four years later. Rijeka was transferred officially to Yugoslavia in 1947 and remained under its rule until Croatian independence in 1991.