by InTrieste
President Sergio Mattarella on Monday marked the 50th anniversary of the Osimo Treaty, describing the landmark agreement as a cornerstone of postwar reconciliation and a turning point in relations between Italy and its northeastern neighbors.
Signed in 1975, the treaty formally settled the long-contested border between Italy and the former Yugoslavia, confirming with legal certainty the status of Trieste as part of the Italian Republic and ending decades of dispute rooted in the turmoil of the fascist era and its aftermath.
“We owe to the Osimo Treaty the definitive attribution, with legal certainty, of Trieste to the Italian Republic and the resolution of divergences over borders — an ungrateful legacy of the fascist war,” Mr. Mattarella said in a statement.
The president emphasized that the agreement marked the close of one of the most painful chapters of modern Italian history, transforming an area once associated with tension and dispute into one of Europe’s most open frontiers. Within years, he noted, the region evolved from a symbol of division into a platform for cooperation — progress later strengthened by Slovenia and Croatia’s accession to the European Union.
“The goodwill of the parties reflected in the agreement made it possible to close one of the bitterest passages of recent Italian history,” Mr. Mattarella said. “It turned those territories, in just a few years, from a painful page into Europe’s most open border, and from a place of sharp confrontation into a place of cooperation.”
He highlighted the treaty’s role as a model for international diplomacy, pointing in particular to the cross-border partnerships that followed and the protection of linguistic minorities on both sides of the frontier. These steps, he said, contributed to reconciliation, stability and shared prosperity in the region.
“The path of reconciliation and broad collaboration with those countries is an example to the international community,” he said, citing the importance of minority protections and local cooperation in “healing wounds, promoting well-being and ensuring stability.”
The Osimo Treaty remains a defining moment in northeastern Italy’s postwar history — particularly in Trieste and the surrounding areas — where memories of shifting borders, population transfers and ideological divisions have long shaped collective identity. For Italy’s head of state, its anniversary is not only a historical marker but a reminder, he suggested, of Europe’s commitment to democracy, the rule of law and peaceful coexistence.
