The manor of Diflais (often anglicized to Dowles, and divided into English and Welsh Dowles) lies in the lordship of Gwynllg (Wentlloog), in p’s Basaleg, Coedcernyw, Marshfield, Llanfihangel-y-fedw, Peterstone Wentlloog, St Brides Wentlloog and St Mellons, and co. Mon. The Manorial Documents Register maintained by the TNA notes a rental (1695) relating to this manor held by the Gwent Record Office.