Still further to the west are the castles of Dorset and Somerset, Devon and Cornwall. Wareham, the ancient Frome-mouth, placed between the Frome and the Piddle, once marked the limits of Poole harbour, and was a place of great strength and fame. As early as 876 its west side, the root of the twixt-waters peninsula, was criticised as weak. In one corner of its rectangular and pseudo-Roman area, a moated mound has been thrown up, as at Tamworth, by the river-side, and its earthworks and position justify its reputation as the key of Purbeck, of which Corfe was the citadel. Corfe, perched upon the summit and slope of a chalk hill between two clefts whence it derives its name, is now a magnificent ruin. Half its noble rectangular keep still stands, and incorporated into the wall of its middle ward is a fragment of the palace of the old West Saxon kings, probably the only material evidence extant that they ever employed masonry in their military works. Of Sherborne, an ancient episcopal seat, the spacious earthwork still contains much of a late Norman keep, and is still entered through a Norman gatehouse. Ilchester and Shaftesbury Castles are gone, and only a part of the earthworks of that of Dorchester remain. West of Purbeck, in Portland, is Bow-and-Arrow Castle, upon the sea-cliff, a curious and somewhat peculiar structure of early date, built or occupied by the De Clares. From Portland to the mouth of the Exe there do not appear to have been any strong places of importance. Just within the mouth of the Exe is Powderham, the work of an Earl of Eu and of De Redvers, and their Courtenay successors, and higher up and opposite, Rougemont, the citadel of Exeter, which still exhibits the high banks, deep ditches, and ancient gatehouse, fragments of the defences behind which the citizens braved the fury of the Conqueror. Inland from the Exe is Okehampton, the earliest of the English possessions of the great family of Courtenay, and the work of Baldwin of Exeter, of the lineage but not bearing the name of De Clare. He was the builder also of Tiverton Castle which is now destroyed, as also is Bridgewater. Among the early castles of the district was Stoke Courcy, now a ruin; Stowey, “pulchrum et inexpugnabile in pelagi littore locatum”; and Dunster, the strongest place in the west, the “Domesday” castle of the Mohuns, and after them, as now, of the Luttrells. In the west of Devon there remains the mound of Plympton, a Redvers castle, and the shell keep of Totnes, the work of Joel of that place, and afterwards inherited by the Barons Braose. Barnstaple town was probably walled, and certainly had four gates. At Taunton a Norman keep and part of a Norman hall still stand on the banks of the Tone, and rise out of earthworks attributed to King Ine. At Montacute, the high ground marked by an immense Romano-British camp, ends in the sharp-pointed hill which William Earl of Moretaine selected for his castle, of which the