Some researchers interpret the evidence of the medieval Llandaff charters to suggest that early Ewyas may have encompassed much of south-east Wales, including the later kingdoms of Gwent and Ergyng.
Geoffrey of Monmouth gives the legend of Octavius (Welsh: Eudaf), "earl of Ewyas and Ergyng", in his famous pseudo-history Historia Regum Britanniae, making him a descendant of Caratacus who had led the Silures in battle against the Romans.
According to Geoffrey, he took up a supposed "British High Kingship" after defeating Trahern, the brother of King Coel Godhebog, in the late third or early fourth century.
[1][2] An 8th-century charter relating to the church at Clodock includes an account of its origin at a time when Clydawg, "king in Ewyas" was murdered while on a hunting expedition, and an oratory was built to commemorate his martyrdom.
[3] Whatever the origins of Ewyas may be, north of the present site of Longtown, a religious centre dedicated to St Beuno was founded at Llanveynoe, where what is probably the oldest stone cross in the modern county of Herefordshire stands, from around 600 AD.