Treaty of London (1915)

The 1915 Treaty of London was the wartime agreement that established the conditions under which Italy entered the war alongside Russia, France, and Great Britain. Its postwar significance lay in the territorial promise it made to Italy: Dalmatia was to be granted in the event of victory. In 1919, that promise became the basis of a public dispute over whether Italy’s sacrifices would be honored at the peace settlement.

The Wartime Promise

The treaty promised Italy Dalmatia, a territory nationalists described as having belonged for centuries to the Republic of Venice. The book presents that commitment as a specific bargain tied to victory, not as a promise of every territory later claimed by Italian nationalists. Fiume, a small border city with a large Italian majority, was excluded from the treaty’s terms.

The Claim at Paris

At the Paris Peace Conference, nationalists joined the treaty’s promise of Dalmatia to a separate demand for Fiume. They argued that Woodrow Wilson’s principle of national self-determination should entitle Italy to the city, producing the slogan “Treaty of London plus Fiume.” Wilson rejected both claims. On April 23, he addressed the Italian people directly in a letter published in a French newspaper, explaining his refusal of Dalmatia and Fiume; the manner of the appeal added to Italian representatives’ sense of being bypassed and humiliated.

Political Consequences

On April 24, Prime Minister Vittorio Emanuele Orlando and Foreign Minister Sidney Sonnino abruptly walked out of the peace conference. In Italy, the refusal was framed as the repudiation of promises made at the cost of 600,000 deaths. Ivanoe Bonomi described the peace conference as seeming to have been conducted “in the light of an ambush.” The treaty thus became part of a wider national grievance: its actual promise of Dalmatia was politically fused with the distinct claim to Fiume, and disappointment over both fed a public mood of deprivation and humiliation.