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
England–Wales border their areas formed into new counties, or amalgamated into existing ones. At this point, the boundary between England and Wales, which has existed ever since, was effectively fixed. In the border areas, five new counties were created – Denbighshire, Montgomeryshire, Radnorshire, Brecknockshire and Monmouthshire – and Flintshire gained some additional territory. However, several of the marcher lordships were incorporated in whole or in part into English counties. The lordships of Ludlow, Clun, Caus and part of Montgomery were incorporated into Shropshire; and Wigmore, Huntington, Clifford and most of Ewyas were included in Herefordshire. According to John Davies: Thus was created