British Kings and Queens @ p. 136
The cited information was published by 1998, Barnes and Nobles (Ref: p. 136) The author/originator was Mike Ashley.
References (6)
Parent Source:
British Kings and Queens
Individual:
King Arthwyr ap Pedr of Dyfed
Individual:
King Pedr ap Cyngar of Dyfed
Individual:
King Cyngar ap Gwrthefyr of Dyfed
Individual:
King Gwrthefyr ap Aircol of Demetia or Dyfed
Individual:
King Aircol ("Lawhir") ap Tryffin of Demetia or Dyfed