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.
Austrian Empire
The Austrian Empire (, modern spelling "") was a Central European multinational great power from 1804 to 1867, created by proclamation out of the realms of the Habsburgs. During its existence, it was the third most populous empire after the Russian Empire and the United Kingdom in Europe. Along with Prussia, it was one of the two major powers of the German Confederation. Geographically, it was the third largest empire in Europe after the Russian Empire and the First French Empire (621,538 square kilometres; 239,977 sq mi). Proclaimed in response to the First French Empire, it partially overlapped with the Holy Roman Empire until the latter's dissolution in 1806.