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
Aspen Institute Wye River Conference Centers section - Wye Woods - is now closed and is being offered for sale.) In 1995 the Conference Center was the site for negotiations between Israel and the Palestine Authority which resulted in the Wye River Memorandum. Since 1998, the Wye River Group on Healthcare has conducted policy meetings on retreat there. Elián González and his father stayed there briefly in 2000. Beginning in September 2008, and meeting quarterly through December 2009, The Aspen Philanthropy Seminar–Washington, DC, convened a small group of philanthropists at the Center. The River House facility was originally developed in 1987 as a specialized high-tech conference