Trieste (trēĕˈstā) [key], Serbo-Croatian Trst, city (1991 pop. 231,100), capital of Friuli–Venezia Giulia and of Trieste prov., extreme NE Italy, on the Gulf of Trieste (at the head of the Adriatic Sea). A major seaport with several shipyards, it is also a commercial and industrial center. Manufactures include machinery, metals, and processed food. Trieste is also the terminus of pipelines from Eastern Europe.
An ancient settlement, it was made a Roman colony (2d cent. B.C.), called Tergeste. It prospered under the Romans, was later held by the Lombards, and was taken by Charlemagne in the late 8th cent. In the 12th cent. it became a free commune. After two centuries of struggle with its rival Venice, Trieste placed itself (1382) under the control of the duke of Austria, although it retained administrative autonomy until the 18th cent. In 1719 it was made a free port. As the sole Austrian port and as a natural outlet for central Europe, Trieste flourished, and in 1867 the crown land of Trieste was made the capital of Küstenland prov.
Despite its Austrian status, Trieste preserved linguistic and cultural ties with Italy. It was a center of irredentism, and after World War I Trieste and its province were annexed (1919) by Italy. However, its prosperity declined under Italian rule. After World War II the area was claimed by Yugoslavia, mainly because the population outside the city of Trieste is predominantly Slovenian. The Western powers opposed Yugoslavia's claim. As a compromise, a new state, the Free Territory of Trieste, was created (1947) under the protection of the UN Security Council. The Free Territory included the city of Trieste and a coastal zone of Istria, running from Duino along the Gulf of Trieste to Cittanova.
When the Security Council was unable to agree on a governor for the territory, Anglo-American forces occupied Zone A, consisting of Italian-speaking Trieste and its environs, while the Yugoslavs occupied Zone B, the remainder of the Free Territory. Tension between Italy and Yugoslavia continued until 1954, when, in a compromise agreement reached under Western auspices, Zone A was placed under Italian administration and Zone B under Yugoslav civil administration (divided between the republics of Slovenia and Croatia). The solution amounted to a partition of the Free Territory, which then ceased to exist; this arrangement was finalized by the Treaty Of Osimo (1975).
Trieste has some Roman ruins, including those of an amphitheater. On a hill commanding a fine view are the Romanesque Cathedral of San Giusto (part of which dates from the 5th cent.) and an imposing castle (14th–17th cent.). On a small promontory northwest of the city is Miramar castle (1854–56), built for Archduke Maximilian of Austria, who sailed from there on his ill-fated Mexican adventure. Trieste has a university, founded in 1924.
See J. Morris, Trieste and the Meaning of Nowhere (2001).