and the castle in Chepstow would also have helped suppress the Welsh from attacking Gloucestershire along the Severn shore towards Gloucester. However, recent analysis suggests that the rulers of Gwent, who had recently fought against King Harold, may initially have been on good terms with the Normans. The precipitous limestone cliffs beside the river afforded an excellent defensive location. Building work started under William FitzOsbern in 1067 or shortly afterwards. The Great Tower was probably completed by about 1090, possibly intended as a show of strength by King William in dealing with the Welsh king Rhys ap Tewdwr. It was constructed in stone from the first (as opposed to wood, like most others built at this time), marking its importance as a stronghold on the border between England and Wales. Although much of the stone seems to have been quarried locally, there is also evidence that some of the blocks were re-used from the Roman ruins at Caerwent. The castle originally had the Norman name of Striguil, derived from the Welsh word ystraigl meaning "river bend". FitzOsbern also founded a priory nearby, and the associated market town and port of Chepstow developed over the next few centuries. The castle and the associated Marcher lordship were generally known as Striguil until the late 14th century, and as Chepstow thereafter. Expansion by William Marshal and Roger Bigod, 1189–1300 Further fortifications were added by William Marshal, Earl of Pembroke, starting in the 1190s. The wood in the doors of the gatehouse has been dated by dendrochronology to the period 1159–89. Marshal extended and modernised the castle, drawing on his knowledge of warfare gained in France and the Crusades. He built the present main gatehouse, strengthened the defences of the Middle Bailey with round towers, and, before his death in 1219, may also have rebuilt the Upper Bailey defences. Further work to expand the Great Tower was undertaken for William Marshal's sons William, Richard, Gilbert and Walter, in the period to 1245. In 1270, the castle was inherited by Roger Bigod, 5th Earl of Norfolk, who was a grandson of William Marshal's eldest daughter, Maud. He constructed a new range of buildings in the Lower Bailey, as accommodation for himself and his family. Bigod was also responsible for building Chepstow's town wall, the "Port Wall", around 1274–78. The castle was visited by King Edward I in 1284, at the end of his triumphal tour