World-famous Vienna State Opera. *Photo from Wikipedia
October 26 is National Day of Austria, celebrates the anniversary of the Declaration of Neutrality in 1955.
Formally, the declaration was promulgated voluntarily by the Republic of Austria.
Politically, it was the direct consequence of the allied occupation by the Soviet Union, the United States, the United Kingdom, and France between 1945 and 1955, from which the country was freed by the Austrian State Treaty (May 15, 1955).
Since then, neutrality has become a deeply ingrained element of Austrian identity. Austria’s national holiday on October 26 commemorates the declaration.
Austria was dominated by the House of Habsburg (House of Austria, Haus Österreich) from 1273 to 1806, when the Holy Roman Empire came to an end.
Austria then became the Austrian Empire, a part of the German Confederation until the Austro-Prussian War of 1866, which Austria lost and was subsequently excluded from German affairs. In 1867 Austria formed with Hungary as a dual monarchy 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 German speaking areas of the empire (its current frontiers), and adopted the name The Republic of German-Austria, with hope of joining the new German Weimar Republic. 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).
In 1938, Austrian-born Adolf Hitler annexed Austria to the German Reich with the Anschluss, which was supported by a large majority of the Austrian people. After the Second World War Austria again became an independent republic as the Second Republic in 1955.
*Reference: Wikipedia