10 November 1975
The Osimo Treaty of October 1975 settled the borders between Yugoslavia (Slovenia) and Slovenian-speaking Italy, accepting the "de facto" division of 1954. The Treaty solidified these boundaries while giving some protection to the Slovene minority in the territory of Friuli-Venezia Giulia. The importance of this treaty relates to the return of archive material, works of art and cultural objects which were removed from the present territory of Slovenia to Italy and Austria between 1941-1945.
Historical background: at the end of World War I, Italy took possession of most of the western Slovene lands which then encompassed almost one third of the Slovene population and included the region of Istria and of the city of Trieste. By 1945 Slovenia had regained most of the Italian Slovene lands, but not Trieste. After the Paris Treaty of 1947, the territory of Trieste was declared international, with Zone A stretching from Duino to Trieste as Allied territory and Zone B from Kiper to Novigrad under the rule of the Yugoslavs.
In 1954 the Allies withdrew from the two occupied zones and left zone A in the hands of Italy and zone B in the hands of Yugoslavia, guaranteeing that the citizens of the two zones could choose within a year of the withdrawal, in which of the two territories they wished to reside but relinquishing all property and assets located in the other territory.
However, the treaty did not resolve the problem of compensation for the loss of assets belonging to people who live in one of the territories, but had some of their assets in the other territory.
Official correspondence from the Slovenian Ministry of Culture (via the Embassy of the Republic of Slovenia in London). Central Registry Archives, 16 April, 2002.