Situated high above the valley of the River Ouse, on the edge of the South Downs, the little Saxon town of Lewes boasts one of the best preserved castle barbican's in England. When William the Conqueror returned to Normandy in 1067, he made grants of land, including the town of Lewes, to one of his lords, William de Warenne. Within a few years Warenne had built an unusual motte and bailey stronghold here, surrounded by defensive earthworks and a moat. Lewes Castle became his main residence, although he did build two other castles, one in Surrey and one in Norfolk. In 1075 the King appointed Warenne joint Chief Justiciar, and soon after that he became the first Earl of Surrey.
The full extent of the oval-shaped bailey constructed by Warenne has been lost among the town's development but both the mottes (mounds), one to the west and one to the east of the bailey, have survived. It is uncertain which is the earlier, but the assumption is that Brack's Mount was the original, smaller outlook post. This may have become redundant at a later date when the larger motte was constructed at the western end of the bailey.
Certainly this was a more strategic site for commanding the town. Experts cannot be absolutely certain about the first building erected on the larger motte, but most are of the opinion that it would have been a simple wooden tower with palisade. During the early 12th century this was replaced by a circular shell keep of flint rubble. From the surviving part of this keep there are fragments of knapped flint set in herringbone masonry, similar to patches found in the ruinous stretch of curtain wall still standing between the bailey and the town.
About 150 years later, two semi-octagonal towers were added to the shell keep at Lewes Castle, and then a range of buildings inside the shell wall. A gate tower was positioned at the foot of the motte, but little of this survives. Almost 300 years after the Norman castle was first erected, a magnificent barbican was added by the 8th Earl of Surrey, John de Warenne. As there was no legitimate heir upon his death in 1347, Lewes Castle became untenanted, and passed into the hands of the earls of Arundel. Already left to decay, Lewes Castle was further damaged in a riot some four decades later and became a source of local building material. By the middle of the 17th century many of the domestic buildings still standing were demolished, but the keep was converted to a summer house in the mid-18th century.
William de Warenne certainly left his mark on the town of Lewes. Not only did he begin an imposing fortress, but he also founded a cluniac priory close by. When he died in 1088 his body was interred in the chapter house. Although only fragments of Warenne's building remains today, it is fitting that it should be remembered by the impressive barbican gatehouse that completed the castle in the 14th century.