The border of 1861 had been established shortly before the Kingdom of Italy between the
Austrian Empire and Italy's predecessors the
Kingdom of Sardinia and its client state the
United Provinces of Central Italy. The border between Austria and the United Provinces had until 1859 been the Austrian border with the
Duchy of Modena and Reggio, and the
Papal States; these had mostly been established in 1815 by the
Congress of Vienna following the
French Revolutionary and
Napoleonic Wars and broadly restored those states to their pre-revolution territories.
Rolo had been Austrian until it was sold to Modena in 1850, and until 1847 part of the border with Modena had been that of the
Guastalla exclave of
Parma and Piacenza. The border with Sardinia itself had been established in the 1859
Treaty of Zürich when Austria ceded the western half of its
Lombardy–Venetia crown land to Sardinia (via France). Italian
Lombardy bordered the Austrian
County of Tyrol in the north-east and the remaining Austrian part of Lombardy–Venetia in the south-east; Austrian Lombardy–Venetia also bordered Italian
Emilia-Romagna to the south. A substantial change occurred in 1866 with the
Treaty of Vienna, which saw the remainder of Lombardy–Venetia ceded to Italy. Much of the border now followed the historical boundary between the
Habsburg Monarchy/
Holy Roman Empire and the
Republic of Venice until the latter was dissolved in 1797, which had been the basis for the Lombardo–Venetian boundary established in 1815. Lombardy continued to border Tyrol; Italian
Veneto bordered Tyrol, the
Duchy of Carinthia and the
Austrian Littoral. Part of this 1866 border survives between the modern Austrian
East Tyrol and
Carinthia and the Italian Veneto and
Friuli-Venezia Giulia. Other parts survive in the boundaries of
Trentino-Alto Adige/Südtirol, and in the
Italy-Slovenia border. Since then the biggest changes to the border were in 1920, when southern Tyrol (what is now
Trentino-Alto Adige/Südtirol) and the area around
Tarvisio were ceded to Italy under the terms of the
Treaty of London and the subsequent
Treaty of Saint-Germain-en-Laye. The part of Tyrol left to Austria was split into two parts –
North Tyrol and East Tyrol – with a small portion of
Salzburg now on the Italian border between them; all three border the now-Italian
South Tyrol. Veneto now bordered East Tyrol and Carinthia. The former Austrian Littoral, with which Italy had shared its eastern border, was also ceded, becoming (along with part of
Carniola)
Venezia Giulia. Carinthia briefly bordered Venezia Giulia, but Tarvisio soon became part of Veneto, separating them. Austrian territories to the east of Venezia Giulia became part of the
Kingdom of Serbs, Croats and Slovenes (later the Kingdom of Yugoslavia). In 1938
Austria was annexed by
Nazi Germany, so its border with Italy became the German-Italian border until
Austria was restored in 1945. When the
Friuli-Venezia Giulia region was established it took over almost all of Venetia's boundary with Carinthia. ==Provinces and states along the border==