Castle comprised an inner bailey around a keep, and an outer bailey between the inner bailey and the N wall of the town. The High Street seems to have been diverted so as to skirt the outer edge of the moat of the inner bailey. The castle was built in the late C11. The walls show evidence of two builds, with only a short interval between, probably the unfinished walls provided with temporary crenellation. There seems to have been no alteration during the Medieval period but the building became ruinous early in the C17. The date of destruction of bailey walls, outer gates, moat filling is uncertain. In 1693 an attempt was begun to destroy the keep but this only extended to the upper storeys and two storeys now remain. The tops of the NE and NW turrets were added about the middle of the C18. At the time of the RCHM survey there were modern prison and museum buildings in the S part of the keep. The rest was unroofed then. The keep walls are of coursed septaria, Roman brick and ragstone with dressings of Roman brick, Barnack, Caen and other freestones. Three angles have square projecting turrets and at the other, SE, angle is a projecting apse. The second storey of the apse is the sub-chapel. The walls of the chapel above survive to a height of 4ft. The main building is divided longitudinally by a cross wall and the larger hall was further divided by a wall or arcade (only S end remains of this). The entrance is on the S, unusually on the ground floor (demolished forebuilding ). At the S end of the building are a wall and a cistern. There was another entrance on the N side at first floor level, now blocked, with an external staircase (gone). In the S wall of the chapel is a reset late C15 - early C16 fireplace. There are several Medieval carvings and graffiti. RCHM has plans and photos. <1> The largest keep in existence, at 152 x 110 ft, ie much more than the White Tower in London. The same type of keep as the latter, ie hall keeps with buildings broader in proportion to height than tower keeps. Traces of a large forebuilding were exposed in 1932. The upper storey was not the main one as it did not include the chapel; there must have been one or two above. The dividing wall of the main area has much herringbone masonry with use of Roman bricks. <2> Built between 1076 and 1086. A new bailey was made round the castle in 1173-4, the walls repaired 1182-3 and the castle strengthened 1214-15. <3> In the first stage the castle was raised to one storey and capped with temporary battlements. Soon after the corner towers were raised one storey. At this time there was a semi-circular bailey to the N. S of the keep there was a chapel and `the south building' (1074-6). The second phase probably resulted in the raising of the keep to three storeys, insertion of a fireplace in the south building and extension of the bailey to the S. (C.1100). Colchester had been handed to Eudo Dapifer in 1073, the castle and town held by him in perpetuity by William II in 1089 (Colchester Chronicle, source 7). There is a reference in 1173-4 to the making of a new bailey which may date to the formation of a lower bailey to the N between the castle and the town wall. <6>
AP photo refs <9> - <11>

Groundworks in the south-east corner of the Castle Bailey revealed only post-medieval and modern features. <13>

Site Management: =Site and keep are listed as well as scheduled. <4> <5>

Site Assessment = "The castle is amongst the moat important remains of Medieval military architecture. In area it is the largest Norman keep now remaining in the country". <1> Largest keep in existence. <2><8>