William fitz Osbern created Roger I de Berkeley as Provost. Roger I de Berkeley took his name from the Manor of Berkeley in Gloucestershire. William fitz Osbern held the Marcher lordship of Striguil, and commenced the building of Chepstow Castle, in Monmouthshire. The name striguil appears to have been derived from a Welsh word "ysttraigyl"= a bend in the river, which being, the River Wye. The Domesday Book spells it as ESTRIGHOIEL and STRIGOIEL. Chepstow had existed as a Saxon town and market place prior to the Norman castle. William fitz Osbern died in 1071, when the Lordship of Striguil passed to his son Roger de Breteuil (born before 1051). Through plotting against King William I , was captured and imprisoned, and forfeited his estates to the Crown. In 1075 he married his sister Emma to Ralph Guader, Earl of Norfolk in defiance of the king's wish, In that same year, immediately after that event Roger de Breteuil and Ralph rebelled. While attempting to unite with Ralph, Roger de Breteuil was prevented from crossing the Severn at Worcester by a fyrd, consisting of the Bishop Wulfstan, Walter de Lacy and other Norman Lords. The term Fyrd was said to have come from the times of King Alfred, and means a Militia. King Alfred had summoned such a militia from three counties to fight a battle. Walter de Lacy had his headquarters at Weobley, Herefordshire. Nest ferch Osbern was a daughter of William fitz Osbern and born about 1081 at Hereford, Herefordshire.