Following the annexation of Austria in 1938, the country, briefly renamed "Ostmark" between 1938 and 1942, was sub-divided into seven "Reichsgaue". These had boundaries broadly the same as the former Austrian "Länder" (states), with the Tyrol and Vorarlberg being merged as "Tyrol-Vorarlberg", Burgenland being divided between Styria and "Lower Danube" ("Niederdonau", the renamed Lower Austria). Upper Austria was also renamed "Upper Danube" ("Oberdonau"), thus eliminating the name of "Austria" ("Österreich" in German) from the official map. A small number of boundary changes also took place, the most significant of which was the massive expansion of Vienna's official territory, at the expense of "Lower Danube".