Austrians
Historically, Austrians were regarded as ethnic Germans and viewed themselves as such. Austria was part of the Holy Roman Empire and the German Confederation until the Austro-Prussian war in 1866 which resulted in Prussia expelling Austria from the Confederation. Thus, when Germany was founded as a nation-state in 1871, Austria was not a part of it. In 1867, Austria was reformed into the Austro-Hungarian Empire. After the collapse of the Austro-Hungarian Empire in 1918 at the end of World War I, Austria was reduced to a rump state and adopted and briefly used the name the Republic of German-Austria ("Republik Deutschösterreich") in an attempt for union with the Republic of Germany, but was forbidden due to the Treaty of Saint-Germain-en-Laye (1919). The First Austrian Republic was founded in 1919. The Third Reich annexed Austria with the "Anschluss" in 1938.
Austrians
The creation of the Czecho-Slovak and South Slav states, the dissolution of the real union with Hungary, and the post-war treaties imposed by the victorious Allies combined to see the newly established Austrian republic both with the boundaries it has today, and a largely homogeneous German-speaking population. In the Treaty of Saint-Germain, in September 1919 the union with Germany was prohibited, and the new republic's name "Deutschösterreich" was prohibited by the treaty; instead the term "Republic of Austria" was used. The westernmost province Vorarlberg's wish to unite with Switzerland was also ignored. On October 21, 1919, the state changed its name accordingly. Many German Austrian communities were left scattered throughout the other new states, especially in Czechoslovakia, where more than 3 million German Bohemians had not been allowed to become part of the new Austrian state, as well as in the southern part of Tyrol which now found itself part of Italy. In total, more than 3.5 million German-speaking Austrians were forced to remain outside the Austrian state.