The 1947 Paris Peace Treaty created the Free Territory of Trieste as a nominally independent buffer state to resolve the competing Italian and Yugoslav claims to the city and its hinterland, but the planned UN governor was never appointed and the territory instead remained split between an Anglo-American military administration in Zone A (Trieste city and a coastal strip) and Yugoslav administration in Zone B (northwestern Istria). The dispute became one of the earliest Cold War flashpoints in Europe. The 1954 London Memorandum ended the arrangement by assigning Zone A to Italy and Zone B to Yugoslavia on a de facto basis, prompting several tens of thousands of ethnic Italians in Zone B to relocate to Italian-administered territory. The border was made permanent only by the 1975 Treaty of Osimo.
The 1947 Paris Peace Treaty created the Free Territory of Trieste, split into an Anglo-American-administered Zone A and a Yugoslav-administered Zone B pending a final settlement; the 1954 London Memorandum divided the territory de facto between Italy and Yugoslavia.
Allied Military Government estimates for 1949 put Zone A at roughly 310,000, comprising some 239,000 Italians and 63,000 Slovenes, and Zone B at about 71,000, where Italian sources counted 36,000-55,000 Italians and 12,000-17,000 Slovenes and Croats. The ethnic breakdown of Zone B was disputed between Italy and Yugoslavia throughout, and remains so.
The 1947-54 existence and 1954 partition of the Free Territory of Trieste was resolved diplomatically by the London Memorandum and caused no significant loss of life; the 1953 Trieste demonstrations killed six people. The killings associated with the wider dispute — the foibe, estimated by the Italian historian Raoul Pupo at 3,000-4,000 victims across all of the former Yugoslavia and Italy, with Italian nationalist accounts citing 11,000 or 20,000 — occurred in 1943-45, before the Free Territory was created. The joint Slovene-Italian Historical and Cultural Commission concluded that local authorities sought to remove Italians and used intimidation, expropriation and economic pressure, but that the evidence does not confirm an intentional Yugoslav policy of expulsion. Between 200,000 and 350,000 Italians left Istria and Dalmatia between 1943 and 1954, the last major wave following the 1954 partition of Zone B.
Italy, Croatia