The Treaty of Vienna, October 3 1866

The Treaty of Vienna put an end to the hostilities caused by the Third War of Italian Independence. It was signed on October 3, 1866, and ratified on the 12^th by the Kingdom of Italy and the Austrian Empire. The agreement led to the transfer of Venetia and Friuli to France and forced Austria to recognise the sovereignty of the Kingdom of Italy.

Background

Since the Revolutions of 1848 Italian nationalists had tried to unify the Italian States into a single nation. However, at that moment many of the Northern states were under the control of the Habsburg monarchy, which had no interest in facilitating a unification. As the Piedmontese knew that their military forces were not strong enough to overcome the Austrians, they sought international support. Consequently, Prime Minister Camillo Benso forged an alliance with France, in which he agreed to cede the provinces of Savoy and Nice to the latter in exchange for military support.

In June 1866 war broke out between Austria and Prussia over Schleswig and Holstein and the German Confederation. As a result, Italy decided to support Prussia and declared war on Austria on June 20. Italy thought that the Austro-Prussian war would allow them to flank the Austrian forces and seize Venice, Friuli, Trentino and Trieste. Still, in the beginning, Austria defeated the Italians at the Battle of Custoza and the Battle of Lissa. Nevertheless, Austria ended up having to seek an armistice after the defeat of its northern armies at the Battle of Sadowa and the rapid advance of the Prussians towards Vienna. The armistice was eventually signed by Austria and Italy on 12 August at Cormons.

The Treaty of Vienna

After the armistice put an end to fighting both Austria and Italy set out to negotiate the terms of a peace treaty, which was signed on October 3,1866, and received the name of the Treaty of Vienna. During the negotiations, Austria agreed to surrender the former Venetian Republic and Mantua. Still, Italy wished to obtain Trentino as far as Salorno, but the Austrians refused by arguing that the armistice of Cormons established the former Kingdom of Lombardy-Venetia as the border and this excluded them.

Moreover, Emperor Franz Joseph was willing to cede Venetia and Mantua to France in exchange for non-intervention in the Austro-Prussian War. However, France ceded them to Italy on 19 October, as they had previously agreed in a secret treaty in exchange for the annexation of Savoy and Nice. As stated in the peace treaty, France held a plebiscite about the annexation to the Kingdom of Italy on 21 and 22 October, in which the population showed overwhelming support for the annexation.

Finally, the Treaty of Vienna forced Austria to acknowledge the sovereignty of the Kingdom of Italy and give it the Iron Crown of Lombardy, the crown worn by the medieval monarchs of Lombardy.

Consequences of the Treaty

The Treaty of Vienna and the Treaty of Prague with Prussia were national humiliations for Austria and its government incurred in a massive state debt. As the Empire was about to collapse, it was forced to sign the 1867 Austro-Hungarian Compromise, which granted autonomy to the Hungarian regions of the Empire. As a result, the Empire was renamed the Austro-Hungarian Empire. Moreover, the fact that it also lost its influence in Italy, reinforced the idea that Austria was now a second-rate power.

On the other hand, the Treaty brought Italy more prestige and made it a great European power. It was also a major milestone for the Unification of Italy since it meant the annexation of Venice and Veneto into the Italian State. Still, many Italian nationalists felt that it was not enough territory, as they had hoped for gaining Trieste and Trentino as well. The desire to claim these regions would be the main reason for Italy’s entry into the First World War against the Austro-Hungarian Empire. Even though Italy was able to acquire Trentino and Trieste in the 1919 Paris Peace Settlement it was not until the occupation of the Dalmatian coast by Fascist Italy that these ambitions were fulfilled.