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.
Germany
In 1871, Germany became a nation state when most of the German states (most notably excluding Switzerland and Austria) unified into the Prussian-dominated German Empire. After World War I and the revolution of 1918–19, the Empire was replaced by the parliamentary Weimar Republic. The Nazi seizure of power in 1933 led to the establishment of a dictatorship, the annexation of Austria, World War II, and the Holocaust. After the end of World War II in Europe and a period of Allied occupation, Austria was re-established as an independent country and two new German states were founded: West Germany, formed from the American, British, and French occupation zones, and East Germany, formed from the Soviet occupation zone. Following the Revolutions of 1989 that ended communist rule in Central and Eastern Europe, the country was reunified on 3 October 1990.