Robert de Belesme, the son of Roger and the third Earl of Shrewsbury, built two castles which played a part in the struggles of the time, and are mentioned by historians. One, Carregchova, was in advance of the frontier, and in Montgomery. It is said to have been built about 1101-2 in great haste. In 1160 it was held and garrisoned by Henry II. It has long been utterly destroyed. The other, Bruges or Bridgenorth Castle, was upon the Severn below and inland of Shrewsbury. Earl Roger had built a castle not far off upon the ancient earthworks of Quatford, opposite to Oldbury, one of the burhs thrown up by Queen Æthelflæda. This castle, of which there remain a mound and a deep well, Earl Robert removed in 1102 to the top of a steep rocky platform above the Severn. It was strong and spacious, and had the church of St. Mary Magdalen for its chapel, and within its area accommodation for some thousands of men. Of all this there remains now little save a fragment of the keep and parts of the containing wall. It was besieged by Henry II. in 1155, and was surrendered for political rather than for military reasons. In advance of the borders of Shropshire are two or three castles of doubtful origin, and which were frequently held by the Welsh. Such were Powis or Pool Castle, attributed to Bleddyn ap Cynfin about 1109; Mathraval, on the Vyrnwy, the residence of the Welsh Princes, but fortified by Robert de Vipont. This was one of the few local castles that resisted the Welsh outbreak of 1212, soon after which it was destroyed. Dolforwin is a small hill-castle on the left bank of the Upper Severn, much resembling Dinas Brân, and far to the west. Deep in the defiles upon the western flank of Cader Idris is the castle of Bere, the remains of which fell into the friendly hands of the late Mr. Wynn of Peniarth, who has shown that the building was of the Early English period of architecture, and unusually ornate in its details. How an early castle came to be placed so far from the border, and in a position by no means abounding in the means of subsistence, is a mystery.