HISTORY IGCSE CONTENT - 20TH CENTURY OPTION - THE ROAD TO WW2: ANSCHLUSS 1938. The Anschluss, also known as the Anschluss Österreichs, refers to the annexation of Austria into Nazi Germany on 12 March 1938. The idea of an Anschluss began after the unification of Germany excluded Austria and the German Austrians from the Prussian-dominated German Empire in 1871. Start date: 12 March 1938.