England–Wales border after Harold's death at the Battle of Hastings, Wales was again divided without a leader to resist the Normans. Immediately after the Norman conquest of England, King William installed one of his most trusted confidants, William FitzOsbern, as Earl of Hereford. By 1071 he had started the building of Chepstow Castle, the first castle in Britain built of stone, near the mouth of the Wye. It served as a base from which the Normans continued to expand westward into south Wales, establishing a castle at Caerleon and extinguishing the Welsh kingdom of Gwent. William also installed Roger de Montgomerie at
Wye Valley the opening of the Severn Bridge (now part of the M48) in 1966. The Wye Valley Area of Outstanding Natural Beauty (AONB) was first designated in 1971. The designation indicates the importance of recognising and preserving the area's distinctive qualities, for the benefit of present and future generations. Administratively the area is very complex, being the only protected landscape to straddle the border between England and Wales. The Counties of Herefordshire, Monmouthshire and Gloucestershire are each in a different government region. Co-ordination of conservation across these political boundaries is undertaken by an AONB unit and Joint Advisory Committee. A Management