History Files

Celtic Kingdoms of the British Isles

Celts of Cymru


MapDogfeilion (Dogfeiling)

FeatureDogfeilion was a minor sub-kingdom inside the eastern border of Gwynedd, bordered to the south by Powys, and forming part of Gwynedd's overall domain. Upon the death of Cunedda Wledig, traditional first king of Gwynedd, his youngest son, Dogfael, gained his inheritance and the land was named in his honour.

MapAt its height, the territory of Dogfeilion seems to have extended much farther east (see the map of Cymru), but this was largely lost to English incursions. The sub-kingdom's royal family, dominated in turn by Powys and Gwynedd, managed to avoid total subjugation by gaining themselves territory in the south of Britain (the sub-kingdom of Glastenning), which Powys did not claim and into which Gwynedd could not easily ride, as well as the sub-kingdom or territory of Pengwern to the west. As a result, they had two armies, one in Dogfeilion/Pengwern and one in Glastenning. This gave them the resources to be major players, with family members in each area. They were able to gain a position of strength in Powysian politics (probably through marriage) and eventually became kings there.

The '-ing' suffix sometimes seen in the Dogfeilion name is an English interpretation (or misinterpretation), showing up as 'Dogfeiling'. The equivalent Welsh suffix is '-ion' and the two seem to have been an automatic translation between the languages, with the Anglo-Saxons habitually substituted 'ing for -ion. The kingdom and its ruling dynasty should more properly be Dogfeilion, although Welsh consonant shifts always leave room for uncertainty. The 'dog' in 'Dogfeil' refers to the deity Dagda (Dog/Dag the Good). The 'feil' is altered 'mail' (mal) which means servant, and is precisely the same word as 'fael' in Cynfael (there were no regular spellings in early records relating to this period). So Dogfeil makes sense as 'servant of Dagda'.

The sub-kingdom's capital may have been at Ruthin. This name was coined for a newly-built red sandstone castle on the site called Rhuthun, from 'rhudd' and 'din', meaning 'red tower', However, it is also known as Castell Coch yng Ngwern-f˘r (seemingly a more modern name), and there seems to have been a wooden tower on the hill prior to the construction of the red sandstone castle. Prior to that a Roman-era fort was built to house a single cohort of legionnaires. This of course would have been modified during the subsequent Romano-British period to serve British cavalry, with a tower as a refuge. It's highly likely that this fort would have continued in use with the men of Dogfeilion.

(Information by Peter Kessler and Edward Dawson, with additional information by Mak Wilson, from The Landscape of King Arthur, Geoffrey Ashe, from Roman Britain: A New History, Guy de la BÚdoyŔre, from History of the Kings of Britain, Geoffrey of Monmouth, from the Historia Brittonum (The History of the Britons), Nennius, and De Excidio Brittaniae et Conquestu (On the Ruin of Britain), Gildas (both J A Giles, Ed & Trans, 1841, published as part of Six Old English Chronicles (Henry G Bohn, London, 1848)), from Marwnad Cynddylan (The Lament for Cynddylan), from the Annales Cambriae, James Ingram (taken from the Harleian manuscript, the earliest surviving version, London, Everyman Press, 1912), and from External Link: English Heritage.)

fl c.445

Dogfael ap Cunedag

Son of Cunedda Wledig of Gwynedd.

fl c.500

Elno / Elnaw ap Dogfael

Son. Gained the Dumnonian sub-kingdom of Glastenning.


Geoffrey of Monmouth's Bishop Eledenius is the little-known St Elidan, a member of the British Church who later has parish churches dedicated in his name in the Vale of Clwyd. This places him firmly within Dogfeilion territory.

fl c.550

Cyndrwyn Glas (the Blue)

Son. King of Dogfeilion & Glastenning. Gained Pengwern.


According to William of Malmesbury, Cyndrwyn Glas settles in Glastenning with his livestock after finding it deserted, migrating there from Luit Coyt (an early connection to this place in Pengwern that will later become important to him and his offspring). His epithet, 'Glas', means 'blue', a typical Welsh naming pun for a redhead. Is this pun the origin of the name Glastenning (and therefore Glastonbury)?

Caer Luit Coyt
The British fort at Caer Luit Coyt (Wall by Lichfield in modern Staffordshire) had been an important staging point on Watling Street, the Roman military road into North Wales, and was inherited and used as a regional capital by the Romano-Britons

Cyndrwyn Glas appears to be a king or sub-king there, and a Cyndrwyn Fawr also appears as a leader in Pengwern around AD 613. Given the links between the Dogfeilion kings and Pengwern, this could also be Cyndrwyn Glas. 'Fawr' means 'great' in Brythonic/Welsh, suggesting that he has built a reputation for himself. Could he also be Cyndrwyn the Stubborn of South Powys, especially given the Powysian dominance over Pengwern which provides direct link between the two?

In terms of Cyndrwyn's personal name, the first part, 'cyn', is 'dog'. This is a common naming form for Celtic leaders, appearing variously as 'cuno', or 'cune', or 'con'. The second part, 'drwyn', is yet another typically Welsh/Celtic pun which is 'trwyn' in modern Welsh, meaning nose, snout, nozzle, proboscis. In other words, Cyndrwyn means 'dog nose'.


While Glastenning is inherited by Morfael, son of Cyndrwyn, this point marks the first appearance of the Dogfeilion in Powys and Pengwern. Morfael is also a sub-king within Pengwern, at Caer Luit Coyt, while his brother, Eiludd Powys, becomes king of Powys (which incorporates the Pengwern territory).

Given Welsh emphasis on ancestry to qualify for a throne, it seems likely that a Dogfeilion leader (probably Cyndrwyn Glas) had married a daughter of the king of Powys, qualifying his descendants to rule Powys by the rules of descent of Gwynedd (which had been inherited from their ancestors, the Pictish Venicones). Romans and Romano-British use primogeniture, but the Pictish rules are that any descendant, regardless of the form of that descent, is qualified to inherit (meaning that even bastard sons of wayward daughters can show up and claim a piece of a territory or even kingship). The fact that the Dogfeilion are accepted as rulers of Powys (and that part of Powys known as Pengwern) is very telling. There has to be a valid claim of descent.

? - c.642

Eiludd Powys (ap Cyndrwyn)

Son. King of Dogfeilion & Powys.


In one of the bloodiest and hardest fought battles of its time, several British kings form a coalition to halt Ăthelfrith of Bernicia at the Battle of Caer Legion (Chester). Cearl of the Mercians could also be involved on the British side (according to scholarly theory). Iago of Gwynedd and Selyf of Powys are both killed, and the battle is a disastrous British defeat. However, Ăthelfrith does not occupy the territory around Chester. Just who does is unknown, and the entire history of this region from the post-Roman period to the tenth century is extremely sketchy. One possibility is that the line of the River Dee is successfully defended by the people living just to the west of it - the Dogfeilion - who are able to claim great prestige from being the victorious defenders of the western Britons. Another possibility is that groups of Angles not under Bernicia's control settle the region to the east of the Dee, and are later subsumed within Mercia.

FeatureBledric ap Custennin, king of Dumnonia, dies at the Battle of Bangor-is-Coed, which follows very soon afterwards. A certain Brochfael is named as the commander of Caer Legion at this time, and may be one of the sons of Powys' Brochfael, potentially the first king of Pengwern. After this, the Dogfeilion kings appear to move in on Pengwern (perhaps due to their theoretical defence of the Dee). The monks of Bangor-is-Coed are present at the battle to pray for divine support, but they too are slaughtered. The act is seen as divine retribution for their refusal to help evangelise the English in 603 (see one of Geoffrey of Monmouth's more accurate entries about this campaign via the feature link).

c.642 - ?

Elaed ap Eiludd

Son. King of Dogfeilion.

652 - 658

Two West Seaxe victories in 652 and 658 see them occupy the entire Glastonbury region, and the sub-kingdom of Glastenning ceases to exist. Its overlord, Dumnonia, also suffers extensive loss of territory in the remaining parts of Somerset and in Dorset. The fate of Morgan Glas, Elaed's cousin in Glastenning, is unknown. The Dogfeilion kings also lose Pengwern in 656, and already seem to have lost control of Pengwern's master, Powys, so now they are cut back to their ancestral territory of Dogfeilion.

The Glastonbury region seems to have experienced a power vacuum in the mid-fifth century which allowed the Dogfeilion to walk in and take over


Marwnad Cynddylan (The Lament for Cynddylan) laments the death of Cynddylan, king of Powys, at the hands of the king of Dogfeilion, marking a resurgence for the Dogfeilion side of the feud. It refers to Cynddylan and his side of the feud as 'the Cadelling', meaning that they are the descendants of Cadell Ddyrnllwg, king of the Pagenses of the mid-fifth century. Cynddylan is 'the battle leader', meaning (in the poet's eyes) the rightful king, and is given a full royal retinue of seven hundred chosen soldiers, the same number that had been beaten by Oswiu of Northumbria in his 656 defeat of Pengwern.

Whether Cynddylan really has that number of men himself is questionable given the fractured nature of Powysian politics at this time and the very recent catastrophic loss of Pengwern. It could be down to poetical largess instead, as a lament of this nature would clearly be written for the court of the dead king, a court that is still resisting Dogfeilion opposition.

fl c.670

Meurig ap Elaed

Son. No known heir, so the territory could revert to Gwynedd.


This branch of Cunedda's descendants ends with Meurig, who is not known to have any offspring. As a consequence, Dogfeilion is very probably brought back under the direct control of Gwynedd, while the remaining Dogfeilion line fights on in Powys to achieve supremacy by around 710-730.