River Wye given a Latin name "Vaga", an adjective meaning 'wandering'. The Tithe map references a Vagas Field in both Whitchurch and Chepstow. Philologists such as Edward Lye and Joseph Bosworth in the 18th and early 19th centuries suggested an Old English derivation from "wæg", "wave". The source of the Wye is in the Welsh mountains at Plynlimon. It flows through or past several towns and villages including Rhayader, Builth Wells, Hay-on-Wye, Hereford (the only city on the River Wye), Ross-on-Wye, Symonds Yat, Monmouth and Tintern, meeting the Severn estuary just below Chepstow. Its total length is . The lower of the
England–Wales border Shrewsbury, and Hugh d'Avranches at Chester, creating a new expansionist earldom in each case. In the Domesday Book of 1086, Norman lands are recorded west of the Wye at Chepstow and Caldicot in the Gwent Levels (); over the whole of north east Wales as far west as the River Clwyd, an area known to the Welsh as the "Perfeddwlad"; and west of Offa's Dyke, especially in Powys where a new castle was named, after its lord, Montgomery. Domesday Book no doubt records the extent of English penetration into Wales. This suggests that Offa's Dyke still approximately represented the boundary