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 England and Wales therefore passes along Monmouthshire's eastern boundaries with Herefordshire and Gloucestershire, essentially along the River Monnow and River Wye. The first legislation applying solely to Wales since the 16th century was passed in 1881. Subsequently, the border between England and Wales has taken on increasing legal and political significance. In 1964 a separate department of state was established for Wales – the Welsh Office – which assumed an increasing range of administrative responsibilities from Whitehall. By 1992, the Welsh Office oversaw housing, local government, roads, historic buildings, health, education, economic development, agriculture, fisheries and urban regeneration, although the