With the advent of the Habsburgs (13th century) the territory was divided between the lords of Duino, Trieste, San Dorligo della Valle and Muggia.

During the reign of Maria Theresa of Austria and, subsequently, Joseph II, the maritime trades were increased with institution of the free port.

After the French definitive defeat, the communes of Duino, Aurisina, Sgonico and Monrupino, which used to be part of Carniola, were annexed to that of Gorizia and Gradisca, while Trieste became a direct city of the Austrian Empire.

World War I left the territory of the province almost untouched, although fierce battles were fought just on its north-westernmost edges.

It comprised the territory of the province at the time of its abolition, as well as significant portions of the Karst Plateau and the region of Inner Carniola in present-day Slovenia.

Italian legislation recognizes and protects the Slovene linguistic minority in all six municipalities of the province, although visual bilingualism is not applied in the city centre of Trieste and in the town of Muggia.

The Istrian dialect is spoken in the municipalities of San Dorligo della Valle and in the rural areas of Muggia, as well as in the southern suburbs of Trieste (most notably in Servola).