The name was also applied to the Marcher lordship which controlled the area in the period between the Norman conquest and the formation of Monmouthshire under the Laws in Wales Acts 1535–1542.
The name – which was spelled in various alternative forms, including Estrighoiel and Strigoiel in the Domesday Book of 1086 – probably derives from the Welsh word ystreigyl meaning 'a bend in the river'.
[3] In the medieval period the town which grew up between the port, the castle, and the priory church became known as Chepstow, from the old English or Saxon ceap / chepe stowe meaning market place.
On his death in 1071, the lordship passed to his son, Roger de Breteuil, but he plotted against King William, was captured and imprisoned, and had his estates forfeited.
[1] The area of the lordship extended east of the River Wye to take in the manors of Tidenham, Woolaston, Beachley and Lancaut, which became part of Gloucestershire in 1535 under the Laws in Wales Act.