History of Austria
Austria was dominated by the House of Habsburg and House of Habsburg-Lorraine ("Haus Österreich") from 1273 to 1918. In 1808, when Emperor Francis II of Austria dissolved the Holy Roman Empire, Austria became the Austrian Empire, and was also part of the German Confederation until the Austro-Prussian War of 1866. In 1867, Austria formed a dual monarchy with Hungary: the Austro-Hungarian Empire (1867–1918). When this empire collapsed after the end of World War I in 1918, Austria was reduced to the main, mostly German-speaking areas of the empire (its current frontiers), and adopted the name The Republic of German-Austria. However the union and name were forbidden by the Allies at the Treaty of Versailles. This led to the creation of the First Austrian Republic (1918-1933).
Treaty of Saint-Germain-en-Laye (1919)
With the Armistice of Villa Giusti on 3 November 1918, the fate of the Austro-Hungarian Monarchy was sealed. On 11 November 1918 Emperor Charles I of Austria officially declared to "relinquish every participation in the administration", one day later the provisional assembly declared German-Austria a democratic republic and part of the German Republic. However, on the territory of the Cisleithanian ("Austrian") half of the former empire, the newly established states of Czechoslovakia, Poland, and the Yugoslav Kingdom of Serbs, Croats and Slovenes (the "successor states") had been proclaimed. Moreover, South Tyrol and Trentino were occupied by Italian forces and Yugoslav troops entered the former Duchy of Carinthia, leading to violent fights.