The remains of Christchurch Castle include parts of the mound-top keep, and more unusually the 12th-century riverside chamber block or ‘Constable’s House’. This very early example of domestic architecture includes a rare Norman chimney.
The estuary on the W. end of Christchurch Bay receives the waters of two streams, the Stour and the Avon, both common names for rivers in England. They, flowing in parallel courses before reaching the salt water, leave a strip of land intermediate between them, which being thus well protected on the E. and W., was occupied in early times with a defensible settlement by the British; and afterwards, the Saxons (probably Edward the Elder on the death of his father Alfred) raised a burh at the highest spot on this neck of land about the year 902, when it was seized by his nephew Ethelwald, who, however, soon left the south country. The name of the place was then Tweoxneham, “the home by the two rivers”, which word became afterwards “Twineham”. It was a very strong position, being surrounded by marshes beyond the rivers. King Edward’s burh, or mound, was of course covered with a timber house, surrounded by a stockade with moat below and palisading. The place seems always to have been a royal vill, and by the Domesday account belonged to the Confessor and then to William I. The ground thus occupied by the castle buildings and enclosure, as likewise by the minster and priory, is on the W. bank of the Avon, near the bridge by which the road crosses; a leat taken off the stream to the priory mill passes along the wall of the Norman house, or constable’s dwelling, and other castle buildings were ranged along this stream, which also filled the moat surrounding the enclosure. This moat ran from the bridge, E. and W., forming the N. defence, and turning S. near the keep mound continued for some 400 yards, when it turned E. at right angles to meet the leat again, thus enclosing a rectangular area in which all the castle buildings were contained, and doubtless originally the early town itself. Inside the moat would, of course, run at first an earthen rampart, to be succeeded by a strong stone wall of curtains between mural towers. The mound in the N.W. corner is oblong, 160 feet by 150, and 20 feet in height, and here it is believed Richard de Redvers built his castle, for whom Henry I. alienated the manor, creating him Earl of Devon. He died in 1139, and the building seems to have been completed by his son Baldwin, who died in 1155. These Redvers, Earls of Devon, had the head of their barony at Plympton Earl, near Plymouth, where are still the ruins of their extensive seat and castle. They succeeded one another till 47 Henry III. (1262), when Baldwin, the eighth and last Earl dying s.p., his estates went to his sister Isabel, who brought them to her husband, William de Fortibus, Earl of Albemarle, a constant supporter of the Barons’ party against Henry III. She was left a widow in 1260, and in 1268 had livery of the Isle of Wight, as heir to her brother, the Earl of Devon (her seal is given by Blaauw), and dying in 1269 left her large possessions to her only surviving daughter, Aveline, who married that year Prince Edmund “Crouchback” (second son of Henry III.), Earl of Lancaster. She died s.p., bequeathing her property to King Edward I., her brother-in-law, who in 1299 assigned this castle and lands to his second wife, Queen Margaret of France, in dower. Edward III. held the place himself, and granted it in his third year to Sir William Montague, whom he afterwards made Earl of Salisbury, for his services in taking Mortimer, Earl of March (see NOTTINGHAM), and whose lands were held by the military service of this castle; Salisbury died seised of it in 1349. Although all the possessions of these Earls of Salisbury were forfeited by the attainder of John, third Earl, on the failure of the conspiracy to restore Richard II., yet Elizabeth, widow of the second Earl, was seised of the castles and lands of the earldom, 2 Henry V. In 32 Henry VI. the castle, hundred, and borough of Christ-church were granted to Richard Nevill, Earl of Salisbury, in right of Lady Alice his wife, heiress of the Montagu family, for twelve years at the annual rent of a red rose. ‘Their son was the great Earl of Warwick, the kingmaker, whose daughter Isabel married George, Duke of Clarence (of the Malmsey butt), and their son Edward, Earl of Warwick, held Christchurch until his forfeiture and murder by Henry VII. in 1499, after which Henry VIII. granted his estates to his sister, the Countess Margaret, married to Sir Richard Pole, until in turn he caused her, too, to be beheaded, 1541, when she was buried in Christchurch minster. 13y descent from her through her granddaughter, Catherine Pole, the inheritors of the Hastings baronies claimed, “the chantry erected for their Plantagenet ancestress in the priory church, they being heirs general” Christchurch remained with the Crown till James I., and was then sold to various persons in succession, being finally purchased by Sir George Rose. It now (1896) belongs to the Hon. Lady Rose.
The keep was a solid rectangular structure, the peculiar feature of which was that its four corners outside were cut off, and so gave the effect of an irregular octagon, without the usual Norman pilasters. (Clark.) Only the E. and W. walls are standing, about 30 feet in height, and with these alone little can be made out of the arrangements. It is very rare to find solid keeps built upon mounds, as generally the lighter “shell” towers were adopted for these situations, or, as at Guildford, the square keep was built partly upon footings which rose from the slopes of the mound.
The other building is that of the constable’s house, near the bridge and by the side of the mil leat; this also is rectangular, measuring 71 feet by 24, haying a garderobe tower projecting at the S.E. corner, built over the leat, whose waters thus flow under and through it. Next to this is a water-gate opening to the leat. Besides this there are two other entrances to the mansion, haying large arches with zigzag and billet mouldings. The hall was on the first floor and occupied the whole space, with its entrance at the S. end under a fine circular-headed doorway. The S. gable and circular window remain nearly entire, and at the N. end is a fine late-Norman double light window, the side walls hawing good windows also; the N.E. corner has fallen. Nothing can be ascertained with certainty as to the origin of this castle, or of the other buildings which constituted it. (Castles Of England, Sir James D. Mackenzie, 1896)