The remains of the medieval castle at Kingerby survive well as a series of substantial earthworks and associated buried deposits. The alteration of the castle in the late medieval period to create a moated manorial site caused limited damage to earlier remains while enhancing the interest and complexity of the site; post-medieval and modern activities have also had a limited effect. Waterlogging in the area of the moat, and the fills of ditches and hollow ways, will preserve valuable evidence for the original construction of the castle and for its alteration and occupation throughout this period.
The remains of the castle are associated with those of an ecclesiastical complex, which also survive in the form of earthworks and buried archaeological layers. The church is a fine example of a medieval parish church showing development and alterations throughout its active history. As a result of historical and archaeological investigation the nature of the remains and their relationship to those of the castle is quite well understood. The churchyard preserves unique evidence for a human population spanning at least a thousand years, while the buried remains of the priory's tithe barn will preserve structural, artefactual and environmental evidence for economic activity on the site. Together, the castle, the church and ecclesiastical complex represent a rare survival of the physical remains of a relationship which was an essential and distinguishing component of medieval society.
The monument includes the remains of a motte and bailey castle, constructed before 1216, and those of an early medieval church and associated ecclesiastical complex. At the time of the Domesday survey the manor of Kingerby was held by the Bishop of Lincoln; in the 12th century it was tenanted by the Amundeville family, who founded an Augustinian hospital (later priory) at Elsham 20km to the north, granting to it the advowson of Kingerby church. During the 12th and 13th centuries a planned village was established around the castle, including an ecclesiastical complex around the church where the priory's holding, including a vicarage and tithe barn, was located. In 1216 the castle was burned and then ordered to be destroyed, following which the motte was altered to create a platform for a moated manorial residence. During the 17th century the village became depopulated as arable land was converted to sheep pasture. In 1812 the late medieval manor house was replaced by the present Kingerby Hall and stable block, which are Listed Grade II and are excluded from the scheduling, although the ground beneath them is included.
The remains of the medieval castle are located on the south side of the present lane immediately south west of St Peter's Church. Kingerby Hall occupies the south western part of a roughly circular platform which is raised approximately 1.5m above the surrounding ground level. This platform is believed to represent the remains of a motte which was partly levelled in the later Middle Ages for the construction of a manor house. The buried remains of the manor house, part of which remained standing until the end of the 18th century, are believed to survive within those of the earlier motte. The platform is surrounded on all sides by the remains of a moat, from which the earth forming the motte was originally excavated. The moat was altered in the post-medieval period as a feature of the gardens of Kingerby Hall; two causeways were constructed on opposite sides of the platform separating the north eastern half of the moat, which continues to hold water, from the south western half, which was partly infilled and is now visible as a broad depression, except in the south western corner where it has been redug to create an ornamental pond. Adjacent to the east and west of the moated platform are the remains of two 'L'-shaped baileys which meet on the south side of the moat; these take the form of raised embanked enclosures bounded around most of the exterior by a shallow depression representing the remains of a hollow way. In the southern part of the west bailey the inner bank has been partly levelled and the hollow way infilled, although it will survive as a buried feature. The northern part of the west bailey is bounded by a linear ditch, beyond which is a broad external bank, overlain by the present lane, which separated it from contemporary house plots adjacent to the north. The remains of the medieval village of Kingerby formerly extended to both the north and west of the castle but have been largely destroyed by modern cultivation and are not included in the scheduling.
The hollow way which runs outside the northern edge of the east bailey is partly overlain by the present lane; approximately 30m west of the church it turns northward where it survives as a broad depression. In the angle of this hollow way are the remains of a large rectangular enclosure representing the holding of Elsham Priory at Kingerby.
Standing on a raised rectangular platform in the south west part of the enclosure is the Church of St Peter, a Listed Grade 1 early medieval church with later alterations. The earliest fabric in the church is believed to date from the 11th century, indicating continuity of occupation over at least a thousand years. The present church consists of a nave with clerestory, south aisle, porch, chancel and western tower. The tower is of three stages of diminishing height with a shallow cornice moulding at the top, made of ironstone repaired with brick. In the east side of the tower, exposed above the nave roof, the earlier roof pitch of the nave can be seen. As this is cut by the 13th century string course, it is likely that this represents a probable 11th century Anglo-Saxon nave roof pitch. The west wall of the nave has a blocked circular window (indicating an Anglo-Saxon/Norman date) and is clearly earlier than the tower, which is built up against it. In addition, inside the tower the butt joint, where the tower was built up against the pre- existing nave west wall can be clearly seen.
The nave's king post-roof is early 17th century and a fine example with four arch-braced moulded tie beams decorated with a carved heart at the west end, and circular rosettes on the undersides of the two central beams. The aisle roof is 18th century. At the west end of the nave at a high level, behind the roof tie beam is a deeply splayed circular opening dating from the early 11th century, which possibly represents the original west light of the Anglo-Saxon church.
The raised platform extends beyond the limits of the present churchyard and is believed to represent its former extent; on the south side it is partly overlain by the present lane. To the north and east of it are the earthwork remains of the western half of the ecclesiastical enclosure, in which the priory's tithe barn was located.
Limited archaeological excavation in this area has demonstrated the survival of below ground remains including stone building foundations. A documentary source of 1270 refers to the presence of a hall and gatehouse. The complex is bounded on the north by a further hollow way, beyond which are the remains of medieval ridge and furrow cultivation extending to the former course of the Kingerby Beck. The eastern part of the enclosure, in which gardens and paddocks may have been located, has been altered by tree-planting and modern cultivation and is not included in the scheduling. (Scheduling Report)