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).
Habsburg Law
On 11 November 1918, Emperor Charles I, counseled by ministers of his last Imperial Royal government as well as by ministers of German Austria, issued a proclamation relinquishing his right to take part in Austrian affairs of state. On the following day, the Provisional National Assembly (Provisorische Nationalversammlung) of German Austria, which claimed authority over the German-speaking portions of the western half of the Habsburg realm (mostly the Danubian and Alpine provinces) proclaimed Deutschösterreich a republic (and a part of the new German republic).