Burgenland School System, was only gradually adapted to Austrian standards on account of that fact that Burgenland had belonged to Hungary up to 1921; German was introduced as the official school language in German-speaking municipalities in 1921; compulsory education was gradually extended from six to eight years in 1923 and in 1929; secondary schools (Hauptschule) were established; a mathematics-oriented selective secondary school (Realgymnasium) was founded in Eisenstadt; a federal schools inspectorate was established; old school buildings were restored, new ones were built, etc. Regulated by Hungarian law dating from 1868, primary education in Burgenland remained basically denominational (in 1937 Burgenland had 23 public primary schools as against 342 denominational primary schools). The Burgenland Education Act of 1937 provided for public financing of denominational schools and their adaptation to Austrian national standards. The special status accorded to schools in Burgenland was finally abolished under Nazi rule in 1938. Despite great efforts by the Church and by parents, denominational schools were not reestablished after 1945.