What is "ewyas"

Ewyas was a possible early Welsh kingdom which may have been formed around the time of the Roman withdrawal from Britain in the 5th century. The name was later used for a much smaller commote or administrative sub-division, which covered the area of the modern Vale of Ewyas (now within Monmouthshire, Wales) and a larger area to the east including the villages of Ewyas Harold and Ewyas Lacy (now within Herefordshire, England).