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.
Germans
During the 1920s, the constitutions of both the First Austrian Republic and the Weimar Republic included the goal of union between the two countries which was supported by all different political parties. In the early 1930s, before the Nazis seized power, popularity for union between Austria and Germany remained strong and the Austrian government looked at the possibility of a customs union with Germany in 1931 but this was stopped by French opposition. In 1933, after Austrian-born Hitler came to power, support for an "Anschluss" grew. The Austrofascism era of Dollfuss/Schuschnigg between 1934-1938 accepted that Austrians were Germans and that Austria was a "German state" but was strongly opposed to Hitler's desire to annex Austria to the Third Reich and wished for Austria to remain independent.