Understanding the descent of the kings of Powys poses considerable problems. These can be resolved when it is realised that the sons attributed to Vortigern (Gwrtheyrn Gwrtheneu) are the offsprings of Cadell Ddyrnllug. The reason behind this intentionally incorrect attribution is given in HB 32-35. It tells how the royals of Powys were descendants of Cadell whose origins were humble. HB 34 tells us Cadell had nine sons. The Harleian manuscript gives the names of five of them, although they are incorrectly listed not as siblings but as sons of each other:
The Pillar of Eliseg mentions four of the sons:
CONCE[NN] PASCEN[T] MAU[N] ANNAN [+] BRITU
The third and fourth elements of this part of the inscription is a reference to a single name, i.e. Mawgan. The PE states they were the sons of Gwrtheyrn. It follows that the name Vortigern was used as an alias for Cadell. Following the above text the inscription reads:
A[ ]T[ ]M FILIUS GUARTHI[ ] QUE(m) BENED[ ] GERMANUS
HB 48 tells us that Gwrtheyrn’s son, Faustus, by his incestuous relation with his daughter, was brought up by Germanus. So, the first word in the above text may be a reference to Faustus. This interpretation is supported by the use of the singular form ‘filius’.
ABT 6k makes no sense as it stands since it suggests Cadell was the son of Pasgen. However, if viewed as two lists, ABT 6k1 and 6k2 as shown below, it illustrates the equivalence of the names Cadell and Vortigern.
|-1||Cyngen Glodrydd||Pasgen||Brydw||Rhuddfedel Frych||Cyndeyrn|
|-2||Cadell Ddyrnllug||Gwrtheyrn Gwrtheneu|
Although the manuscript states Nest was the mother of Merfyn Frych the above table shows her as his wife. This is indicated as being the case in JC 18.
As noted by Phillimore the name Cateyrn has been ‘tortured’ into the form Cyndeyrn by later genealogies. Vermaat explains the presence in the list of Rhuddfedel as a reference to the battle at Rithergabail where Cateyrn died.
 Cy IX, 179 n. 5
 Vortigern Studies > Vortigern > The Family of Vortigern > Catigern, son of Vortigern