Diocese of Trieste and Capodistria
The diocese of Trieste and Capodistria is a former diocese of the Roman Catholic Church . It was founded on June 30, 1828 by amalgamating the dioceses of Capodistria (Koper) and Trieste .
Capodistria belonged to the Maritime Republic of Venice until 1797 , then under Austria to the margraviate of Istria (part of the Austrian coastal region ). Trieste had been Austrian since 1382 with the status of an imperial city . Capodistria was also largely inhabited by Italians until the end of the Second World War.
On October 17, 1977 - two years after the Treaty of Osimo , in which Trieste finally annexed Italy and Koper to the Yugoslav state - the two dioceses were separated again.