Formally resolved the postwar status of the Free Territory of Trieste by dividing it between Italy and Yugoslavia along a definitive border.
Key Facts
- Signing date
- 10 November 1975
- Effective date
- 11 October 1977
- Zone A (to Italy)
- Trieste and narrow north-western coastal strip
- Zone B (to Yugoslavia)
- North-western part of Istrian peninsula
- Treaty language
- French
- Italian signatory
- Mariano Rumor, Minister for Foreign Affairs
Location
Cause → Event → Consequence
After World War II, the Peace Treaty of 10 February 1947 left the status of Trieste unresolved by establishing the Free Territory of Trieste, a contested region claimed by both Italy and Yugoslavia. Decades of diplomatic tension and ambiguity over the precise frontier necessitated a formal settlement.
On 10 November 1975, Italian Foreign Minister Mariano Rumor and Yugoslav Federal Secretary Miloš Minić signed the Treaty of Osimo in Osimo, Italy. The agreement partitioned the Free Territory of Trieste, awarding Zone A including the city of Trieste to Italy and Zone B on the Istrian peninsula to Yugoslavia.
The treaty, entering into force on 11 October 1977, definitively closed the postwar Trieste question and established a legally recognized border between Italy and Yugoslavia, replacing the ambiguous provisional arrangements that had persisted since 1947.
Political Outcome
Free Territory of Trieste partitioned: Zone A to Italy, Zone B to Yugoslavia; border delimited definitively.
Free Territory of Trieste under provisional administration, border undefined since 1947
Trieste formally Italian; Istrian Zone B formally Yugoslav; definitive border established