Signing of the Treaty of Rapallo

The Signing of the Treaty of Rapallo reshaped the Adriatic settlement and exposed the widening rift between diplomatic compromise and the uncompromising claims made in Fiume. Italy accepted a border at Monte Nevoso and the loss of Dalmatia, while Fiume was recognized as independent but cut off from maritime trade with the East. Benito Mussolini backed the agreement even as Fiume’s fascists denounced it, making the treaty both a territorial settlement and a test of his political authority.

Terms of the Settlement

Announced unexpectedly on November 12, 1920, the Treaty of Rapallo addressed the Adriatic question between Italy and Yugoslavia. Italy’s eastern border was moved to Monte Nevoso, leaving Trieste secure. The larger concession was Dalmatia: Italy relinquished the region and received only Zadar, without an inland hinterland or the neighboring islands. The arrangement left Zadar as an Italian outpost surrounded by Croatian territory.

Fiume’s status was a separate compromise. It was granted full independence rather than assigned to either Italy or Croatia, but Sussak, its eastern coastal suburb, went to Croatia, including Port Baross. The result deprived Fiume of access to maritime trade with the East. To supporters of Italian annexation, the settlement therefore preserved the city’s separate status while stripping that status of much of its practical promise.

Mussolini’s Endorsement and the Party Division

On November 15, from the columns of Il Popolo d’Italia, Mussolini declared himself “frankly satisfied.” He distinguished Fiume’s position from the rest of the settlement but described the agreement as the best among the proposals previously advanced. On Dalmatia he objected to postponing the possibility of revision, maintaining that peoples’ rights did not expire; nevertheless, he openly approved the compromise reached by Giovanni Giolitti.

That endorsement provoked an immediate response in Fiume. Even fascists who held party cards joined a bonfire in Piazza Dante, burning bundles of Il Popolo d’Italia containing the offending article, and sent the newspaper a bitter telegram. The accusation of betrayal circulated openly. The dispute was not merely over borders: Mussolini’s approval placed national discipline and political calculation against the claims of those who regarded D’Annunzio’s project as an unfinished national revolution.

At the Central Committee meeting of the Fasci Italiani di Combattimento on November 15, the division became visible around the table. Cesare Rossi, Massimo Rocca, and Umberto Pasella stood with Mussolini; Cesare De Vecchi, Piero Belli, Pietro Marsich, and other committed supporters of Fiume opposed him. A delegation of Dalmatians stood along the wall. Mussolini argued that the new borders in Venezia Giulia and Fiume were acceptable overall, though the terms concerning Dalmatia were not. The country was exhausted, he warned, and the socialists could exploit a crisis; he also argued that many Italians did not know where Dalmatia was. He called for acceptance as a matter of national discipline and proposed an agenda reflecting that position. In his account, D’Annunzio’s spectacular sedition had become gangrenous and had to be cut away.

Marsich, head of the Venetian fasci and a fervent D’Annunzian, attacked the agreement and insisted that the Fiume movement would continue. The debate sharpened when the Dalmatians spoke of their Italian identity and the prospect of being placed under Croatian rule. Their appeal stirred the room, making the committee’s dispute more than a contest between party factions: the treaty had brought claims of national belonging directly into conflict with the demand for political discipline.

From Treaty to Blockade

The settlement’s implementation turned the dispute into a confrontation. At the beginning of December, General Enrico Caviglia, commanding the force sent from Rome to enforce the Treaty of Rapallo, ordered D’Annunzio to evacuate Veglia and Arbe, towns occupied in defiance of the treaty. On December 20, Caviglia issued a further ultimatum: D’Annunzio had forty-eight hours to bring his legionnaires back within the borders of the Fiume state recognized by the agreement. Caviglia also imposed an effective blockade of Fiume by land and sea.

D’Annunzio answered with three proclamations in twenty-four hours. He urged Italian sailors involved in the siege to disobey orders; in another proclamation he declared that Fiume had been sold out and that resistance, even death, was the remaining duty. A third appeal addressed the mothers of soldiers who might be ordered to attack their countrymen defending Fiume’s Italian character. The treaty had thus moved beyond diplomatic terms into a direct challenge to the obedience of Italian forces.

Mussolini, meanwhile, protested the blockade and urged Giolitti to recognize the D’Annunzian Regency officially. He condemned the prospect of Italian soldiers attacking Italian legionnaires as an ineradicable crime, called the blockade “barbaric coercion,” and threatened terrible consequences, while still expressing confidence that blood would not be spilled. His stance exposed the strain within his own position: he had endorsed the treaty as a necessary compromise, yet opposed coercive measures against the Fiume regime it was meant to contain.

Political Significance

The treaty established a diplomatic settlement but did not reconcile the competing claims it had rearranged. Italy secured its eastern border and retained Zadar, while Dalmatia was relinquished and Fiume’s independence came with territorial and commercial limitations. In Fiume, the burning of Mussolini’s newspaper and the language of betrayal showed how sharply the compromise diverged from the expectations fostered by the city’s supporters.

For Mussolini, the episode required choosing between the immediate claims of the Fiume movement and a broader strategy of accepting an agreement he considered the most workable available. The party committee’s divided ranks, the Dalmatians’ protest, and the later blockade made that choice visible in successive forms: first as an argument over discipline, then as a struggle over who would enforce the treaty. The settlement closed one diplomatic question only by opening a confrontation over Fiume’s political future.