Previously uninhabited hills and swamps, the town of Asch was founded in the early 11th century by German colonists descending from the Bavarian march of the Nordgau in the course of the "Ostsiedlung". So far, previous Slavic settlements in the area are not known. Similar to the Egerland region, the dialect spoken in the town was that of the Upper Palatinate region in the south, also known as Northern Bavarian. In the adjacent Saxon Vogtlandkreis to the east, this dialect is only found in localities close to the Czech border, such as Adorf and Markneukirchen. The Upper Palatinate dialect has a stronger presence in the Bad Brambach area, where it is known as Southern Vogtlandic ("Südvogtländisch").