With the reformation in the 16th century the national language was installed in church instead of Latin. In Slesvig this meant not the language of the peasantry, but that of the dukes and gentry, being first Low German and later High German. German was the language of administration in all of Slesvig. In Northern Slesvig, however, priests were educated at the chapter of Haderslev and Danish was spoken in church. The church language border was very similar to the present-day Danish-German border which was created by plebiscite in 1920.