History Files


Celtic Kingdoms of the British Isles

Celts of Cymru




Map Builth (Buellt)

The kingdom was centred on Caer Bedris in Builth, in modern Powys. It was apparently founded as an offshoot of Powys by the Powysian Vortigern's son. Apparently his claim was confirmed by Ambrosius Aurelianus at Caer Gloui after Vortigern's death.

The sub-kingdom or region of Gwrtheyrnion was part of Builth's territory, and the kings often seem to bear the title king of Guorthegirnaim (Gwrtheyrnion).

c.406 - 440

Pascent / Pasgen ap Gwrtheyrn

Third son of Vortigern. Given Builth & Gwrtheyrnion by his father.

Geoffrey of Monmouth proposes an almost entirely mythical account of the life of Ambrosius Aurelianus and of Pascent, who remain enemies throughout their lifetimes. Utherpendragon sets out to attack the Saxons involved in his brother's death, who have teamed up with 'Paschent' and a young nobleman of Ireland named Gillomanius. Uther defeats them all, killing Paschent and Gillomanius.

c.440 - 475

Braciat / Braigad ap Pasgen


fl c.442

Morgan ap Pasgen

Brother. Joint ruler?

c.455 - 800

One of the results of the messy situation in the east, following the Jutish foederati takeover of Ceint and the death of Vortigern, is that Gwrtheyrnion now passes to his sole surviving (legitimate) son. Nennius states that this is 'granted' by Ambrosius Aurelianus, but it is probably little more than a rubber stamp. Pascent governs the principality directly from Builth, although he has probably already exercised regional control over it from the point at which it had first been divided from Pagenses. In fact, it would seem that Pacent is already deceased by this time and that it is his son, Braciat, who now governs Built and Gwrtheyrnion - a fine detail that may have been lost to some chroniclers.

c.475 - 510

Idnerth ap Briagad

Son of Braciat.

c.510 - 545

Meuprit / Meurig ap Idnerth


c.545 - 580

Pau / Pawl ap Meurig

Son. Sub-king to Brycheiniog for a time.

c.580 - 615

Eltat / Elaed ap Eldoc ap Pawl


c.615 - 650

Moriud / Morwd ap Elaed


c.650 - 685

Guoidcant / Gwyddgan ap Morwd


c.685 - 715

Pascent / Pasgen Buellt


c.715 - 745

Teudor / Tedwr ap Pasgen


fl c.720

Glowd ap Pasgen

Brother. Joint ruler?

fl c.785

Braustud ferch Glowd

Dau. m Arthfael Hen (the Old) of Glywyssing.

c.745 - ?

Fernvail / Ffernfael ap Tewdr

Uncle. Last king of Builth & Gwrtheyrnion

by 800

Fernvail's fate is unknown, as are any firm dates for his life and reign. If the estimate of AD 745 for the start of his reign is remotely accurate then it is unlikely that he lasts as long as 800, but other estimates place him around this later period. A collection of medieval genealogies held in the Bodleian at Oxford - Jesus College MS20 - show him as a contemporary of Arthfael Hen ap Rhys of Glywyssing (Arthfael marries his cousin, Brawstudd, but presumably early in his life rather than later).

This king can be placed anywhere in the last quarter of the eighth century and first quarter of the ninth century, so using AD 800 as a rough point for the presumed death of Fernvail seems appropriate. Afterwards, Builth and Gwrtheyrnion cease to exist as separate Welsh territories in their own right, being absorbed by Seisyllwg and then Deheubarth. The precise circumstances and process by which this happens are unknown.