In Culhwch ac Olwen,during his chase, Twrch Trwyth killed Llygadrudd Emys and Gwrfoddw, Arthur’s uncles, his mother’s brothers. The latter name appears in that of Gwrfoddw Hen, king of Ergyng, but he appears to be a later ruler. However, Welsh dynasties often preserved the same name, so Gwrfoddw Hen may have been a descendant. This suggests Eigr, Gwrfoddw’s sister, could have come from that region.
Ergyng may have covered parts of Herefordshire, Monmouthshire and Gloucestershire. The Brut y Brenhinedd calls Eudaf, an ancestor of Arthur, as “Eudaf yarll ergig ac euas”, that is Earl of Ewyas and Ergyng. However, Geoffrey refers to him anachronistically as “Octavius dux Wisseorum”, presumably the territorial name being derived from Welsh Ewyas.
Magnus Maximus had a daughter, named Sevira, by Elen, daugther of Eudaf. It was through Gwrtheyrn’s marriage with Sevira that he gained control of the territory that was to become known as Ewyas. Geoffrey referred to him as the “Consol Gewissiorum”. He invited Germanic warriors to settle in the Abingdon area to help defend attacks on his territory in Ergyng. The ASC confuses this event with the later settlement in Kent. The name for Gwent is easily confused with that for Kent. Gwrtheyrn locating the Gewisse, a Saxon tribe, in the upper Thames valley made logistical sense, as his opponent, Emrys Wledig i.e. Aurelius Ambrosius, was based in the Wiltshire area. Located in that county is the village of Amesbury, formerly known as “Ambres byrig” in the Cartularium Saxonicum. It is likely that the East Wansdyke earthwork was built by the Britons as a defense against attack from the north.
Cerdic is attributed in the Anglo-Saxon Chronicle as the founder of the Wessex dynasty. However, as Dumville has pointed out, his reign started later than the chronicle suggests. In fact, he belonged to a second Wessex dynasty. The first dynasty was founded by the eponymous ruler, Wig/Giwis, the two names being, as Sisam explains, alliterative pairs. His reign was followed by that of Esla/Elesa. The latter is known as Osla Gyllellfawr, whose defeat by Arthur brought the first Wessex dynasty to an end. For obvious reasons, this disaster goes unmentioned in the ASC.