strait which formed the haven, whereby not only would the inhabitants be deprived of their chief hope of succour, but the waters, checked in their course and thrown back upon themselves, would swell into a mighty flood and speedily overwhelm the city. Meanwhile, added the supporters of this scheme, Stephen might build a tower on each side of the city to check all ingress and egress by means of the two bridges, while he himself should encamp with his host before the castle and storm or starve it into surrender. Another party, however, whose secret sympathies were with the besieged, argued that whatever material, wood or stone, was used for the construction of the dam would be either swallowed up in the depths of the river or swept away by its current; and they drew such a dismal picture of the hopelessness of the undertaking that Stephen gave it up, and with it all attempt at a siege of Bristol. Turning southward, he struck across the Mendip hills into the heart of Somerset, and besieged William Lovel in Castle Cary,[776] a fortress whose remains, in the shape of three grass-covered mounds, still overlook a little valley where the river Cary takes its rise at the foot of the Polden hills. According to one account, the place yielded to Stephen;[777] according to another,[778] he built over against it a tower in which he left a detachment of soldiers to annoy its garrison, and marched northward to another castle, Harptree, whose site is now buried in the middle of a lonely wood. Harptree was gained by a stratagem somewhat later on;[779] for the present Stephen left it to be harassed by the garrison of Bath, and pursued his northward march to Dudley. Here he made no attempt upon the castle, held against him by Ralf Paganel, but contented himself with burning and harrying the neighbourhood, and then led his host up the Severn to Shrewsbury.[780] The old “town in the scrub,” or bush, as its first English conquerors had called it, had grown under the care of its first Norman earl, Roger of Montgomery, into one of the chief strongholds of the Welsh border. The lands attached to the earldom, forfeited by the treason of Robert of Bellême, had been granted by Henry I. to his second queen, Adeliza; she and her second husband, William of Aubigny, had now thrown themselves into the party of her stepdaughter the Empress; and the castle built by Earl Roger on the neck of a peninsula in the Severn upon which the town of Shrewsbury stands was held in Matilda’s interest by William Fitz-Alan, who had married a niece of Robert of Gloucester.[781] William himself, with his wife and children, slipped out at the king’s approach, leaving the garrison sworn never to surrender. Stephen, however, caused the fosse to be filled with wood, set it on fire, and literally smoked them out.[782] The noblest were hanged; the rest escaped as best they could,[783] while Stephen followed up his success by taking a neighbouring castle which belonged