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).
Red Vienna
After World War I had ended with the collapse and dismemberment of the Habsburg dual monarchy of Austria-Hungary, "Deutschösterreich" (Republic of German-Austria) was proclaimed a republic on November 12, 1918. At the "Gemeinderat" (city parliament) elections of May 4, 1919, for the first time ever all adult citizens of both sexes had voting rights. The Social Democratic Party gained an absolute majority; Jakob Reumann was elected first social democratic mayor, to be succeeded in 1923 by Karl Seitz.