The Austro-Hungarian Empire played a decisive role in central European history. It occupied strategic territory containing the southeastern routes to western Europe and the north-south routes between Germany and Italy. Present-day Austria retains this unique position.

Soon after the Republic of Austria was created at the end of World War I, it faced the strains of catastrophic inflation and of adapting a large government structure to the needs of a new, smaller republic. In the early 1930s, worldwide depression and unemployment added to these strains and shattered traditional Austrian society. In 1933, Engelbert Dollfuss formed a conservative autocracy. In February 1934, civil war broke out, and the Socialist Party was outlawed. In July, a coup d'etat by the National Socialists failed, but Nazis assassinated Dollfuss. In March 1938, Germany occupied Austria and incorporated it into the German Reich. This development is commonly known as the "Anschluss" (annexation).

At the Moscow conference in 1943, the Allies declared their intention to liberate and reconstitute Austria. In April 1945, both Eastern- and Western-front Allied forces liberated the country. Subsequently, the victorious allies divided Austria into zones of occupation similar to those in Germany with a four-power administration of Vienna. Under the 1945 Potsdam agreements, the Soviets took control of German assets in their zone of occupation. These included 7% of Austria's manufacturing plants, 95% of its oil resources, and about 80% of its refinery capacity. The properties returned to Austria under the Austrian State Treaty. This treaty, signed in Vienna on May 15, 1955, came into effect on July 27, and, under its provisions, all occupation forces departed by October 25, 1955. Austria became free and independent for the first time since 1938.