 High Prussian dialects were spoken mainly in the Catholic region of Warmia and adjacent East Prussian ' region beyond the Passarge River in the west (around Preußisch Holland and Mohrungen), subdivided into ' (from Silesian Breslau) and "".They were separated from the Low Prussian dialect area by the Benrath line isogloss to the west, north and east; to the south they bordered on the Polish Masurian dialect region.Like Silesian German, High Prussian is moribund due to the evacuation and expulsion of the German-speaking population from the Province of East Prussia during and after World War II.