In the 16th century, the Mawddwy area was home to a band of highway robbers and bandits named the 'Gwylliaid Cochion Mawddwy' or 'Gwylliaid y Dugoed'. The Gwylliaid were supposedly the dregs of society, who came to the Dinas Mawddwy area having been excommunicated from their own areas.
In the 16th century, the Mawddwy area was inhabited by a band of highway robbers and bandits known as the 'Gwylliaid Cochion Mawddwy' or 'Gwylliaid y Dugoed'. The Gwylliaid were supposedly the lowest members of society who had been cast out from their own communities.