Italy renounces the Triple Alliance

On 4 May 1915 the Italian ambassador in Vienna, the Duke Giuseppe Avarna, handed the Austro-Hungarian foreign minister, Baron István Burián, a note from his government. In it Italy declared that it regarded its alliance with Austria-Hungary as broken. The foreign minister Sidney Sonnino had sent the instruction from Rome the day before, which is why some studies, and also the Polish Wikipedia, give 3 May as the date of the renunciation of the Triple Alliance. The Italian government itself, in its later declaration of war, wrote that the reasons for this decision had been communicated to Vienna on 4 May.

The content of the note

Rome justified its step in the same way as in August 1914, when it declared neutrality. Austria-Hungary had attacked Serbia without consulting its ally and without regard for its interests, and had thus itself broken the treaty, which required the two states to agree on any changes in the Balkans. Months of negotiations on compensation for Italy, conducted since December 1914, had produced no result, because Vienna’s offers were, in Rome’s view, too meagre. Italy therefore withdrew all its previous proposals, declared that the treaty of alliance with Austria-Hungary was henceforth void and without effect, and announced that it was resuming full freedom of action.

The note concerned only Austria-Hungary. The Triple Alliance, concluded in 1882 and last renewed in December 1912, also bound Italy to Germany, but Rome did not declare war on Berlin and wanted, as far as possible, to avoid open conflict with it. The German government was merely informed of the step taken in Vienna. Burián was taken by surprise. He believed that the talks, in which Vienna had gradually agreed to ever greater concessions, were heading towards an agreement.

A secret decision

Few knew why Rome had broken off the negotiations at that particular moment. On 26 April Italy had signed a secret treaty with the Entente in London and undertaken to enter the war within a month. Renouncing the alliance was the first step on that road. The government did not, however, announce it publicly. Most deputies, gathered around the former prime minister Giovanni Giolitti, still favoured neutrality, and parliament was not due to meet until 20 May. According to some sources, news of the renunciation of the alliance leaked to the press a few days later. Sonnino officially presented the documents to parliament on 20 May, in the so-called Green Book.

Tension in Italy grew by the day. On 5 May at Quarto near Genoa, from where exactly 55 years earlier Garibaldi’s expedition had set out for Sicily, the poet Gabriele D’Annunzio delivered a fiery speech calling for war before a crowd estimated at about 20,000 people. Austria-Hungary, pressed by Germany, made new, more far-reaching offers of concessions in the following days, and the former German chancellor Bernhard von Bülow, ambassador in Rome, hoped that the neutralists might still restrain the government. On 9 May Giolitti arrived in the capital. In mid-month Italy went through an acute political crisis, and on 23 May it declared war on Austria-Hungary.