 After World War I the name "Sudetenland" came into use to describe areas of the First Czechoslovak Republic with large ethnic German populations.In 1918 the short-lived rump state of German-Austria proclaimed a Province of the Sudetenland in northern Moravia and Austrian Silesia around the city of Opava ("Troppau").The term was used in a wider sense when on 1 October 1933 Konrad Henlein founded the Sudeten German Party and in Nazi German parlance "Sudetendeutsche" (Sudeten Germans) referred to all indigenous ethnic Germans in Czechoslovakia.