The monument includes an Augustinian monastery and an earlier medieval manorial residence situated on a clay hill which overlooks Romney Marsh to the south. The monastery and moated site survive in the form of standing buildings, water-filled fishponds, earthworks and associated below ground remains. Dedicated to St Mary the Virgin and St Nicholas, the monastery was founded in 1253 by Sir John Mansell, Lord Chief Justice of England and Lord Warden of the Cinque Ports. Mansell had the monastic buildings constructed at the manorial centre of Upper Bilsington, endowing the monastery with the surrounding demesne lands. The roughly square, north east-south west aligned moat which lies within the southern part of the monument is believed to represent the pre-existing, moated medieval manor house. The north eastern arm of the moat has become infilled, but will survive as a below ground feature. The central part of the moated island is now occupied by The Priory, a large private residence built in 1906. The construction of the modern house, along with associated garden landscaping, has partly disturbed this area of the monument. The Priory is excluded from the scheduling although the ground beneath is included. Below ground traces of the manorial centre and later monastery can be expected to survive on the moated island in the areas beneath and around the modern house. Situated towards the eastern edge of the monument, the main monastic buildings were arranged around a square, north west-south east aligned cloister yard. The standing, `L'-shaped ranges are mainly constructed of originally plastered ragstone rubble, decorated with ashlar dressings and topped by clay-tiled roofs. Internally, there has been some reconstruction in red brick. The buildings are thought to represent the southern, refectory range, with the abbot's and guest lodgings attached to its south eastern corner. The main, north west-south east aligned refectory range is two-storeyed, housing a first floor hall above a plain undercroft, used originally for storage. The main entrance is approached through a timbered porch attached to the north western gable end. The range has a restored roof supported by three crown post trusses. The abbot's and guest lodgings incorporate a three-storeyed, square tower with a hipped roof, and a cross-wing projecting to the south west. The buildings are linked by a three-storeyed staircase turret at their north eastern angle. Historical records indicate that the monastic buildings were constructed in the years between 1253-58, with some later additions. Many original medieval features survive, although subsequent work, in particular the major restoration of 1906, which involved the almost complete rebuilding and heightening of the cross wing, have altered the form and appearance of the buildings. In situ medieval features include the original doorway through the north western gable end of the refectory range, corner buttresses supporting the refectory and the tower, blocked doorways in the northern refectory wall, some original windows and a fireplace in the tower chamber. The standing buildings including The Priory are Listed Grade I. Investigations carried out in 1952 indicated that the other main claustral buildings, including the monastic church, survive as below ground archaeological features in an area of hummocky ground to the north east of the standing ranges. Buried traces of the gatehouse, providing the original access into the monastic precinct and subsequently incorporated into now demolished farm buildings, will survive in the north eastern corner of the monument. Further associated below ground remains, including any subsidiary cloisters and the monastic burial ground, can be expected to survive within the areas surrounding the main cloister. Two large, irregular fishponds, constructed in the northern part of the monument, and a third smaller pond which reuses the north eastern part of the moat, helped to supply the monastery with fresh fish. Bilsington Priory was dissolved in 1536, and ownership passed for a time to Thomas Cranmer, Archbishop of Canterbury. Much of the monastery was demolished and the surviving buildings reused as a farmhouse throughout the post-medieval period. During the early 19th century, local smugglers known as the Aldington Gang used the monastic buildings for the storage of contraband. The buildings fell gradually into decay before the major restoration of 1906. The grounds were used for army training during World War II, which will have caused some disturbance to the monument. A number of features are excluded from the scheduling; these are The Priory (the private dwelling built in 1906), the early 20th century road bridge over the moat, the modern footbridge giving access onto the north eastern fishpond island, all modern outbuildings, garden structures and features, all modern fences and gates, and the modern surfaces of all roads, tracks, paths, paving and hardstanding; the ground beneath all these features is, however, included. ASSESSMENT OF IMPORTANCE From the time of St Augustine's mission to re-establish Christianity in AD 597 to the reign of Henry VIII, monasticism formed an important facet of both religious and secular life in the British Isles. Settlements of religious communities, including monasteries, were built to house communities of monks, canons (priests), and sometimes lay-brothers, living a common life of religious observance under some form of systematic discipline. It is estimated from documentary evidence that over 700 monasteries were founded in England. These ranged in size from major communities with several hundred members to tiny establishments with a handful of brethren. They belonged to a wide variety of different religious orders, each with its own philosophy. As a result, they vary considerably in the detail of their appearance and layout, although all possess the basic elements of church, domestic accommodation for the community, and work buildings. Monasteries were inextricably woven into the fabric of medieval society, acting not only as centres of worship, learning, and charity, but also, because of the vast landholdings of some orders, as centres of immense wealth and political influence. They were established in all parts of England, some in towns and others in the remotest of areas. Many monasteries acted as the foci of wide networks including parish churches, almshouses, hospitals, farming estates and tenant villages. Some 225 of these religious houses belonged to the order of St Augustine. The Augustinians were not monks in the strict sense, but rather communities of canons - or priests - living under the rule of St Augustine. In England they came to be known as `black canons' because of their dark coloured robes and to distinguish them from the Cistercians who wore light clothing. From the 12th century onwards, they undertook much valuable work in the parishes, running almshouses, schools and hospitals as well as maintaining and preaching in parish churches. It was from the churches that they derived much of their revenue. The Augustinians made a major contribution to many facets of medieval life and all of their monasteries which exhibit significant surviving archaeological remains are worthy of protection. The Augustinian monastery at Bilsington survives well, despite some subsequent disturbance, in close association with an earlier medieval moated manor house, and retains high quality standing buildings and water-filled fishponds. Part excavation has confirmed that the monument also contains important archaeological and environmental evidence relating to the original form, use and development of the monastery and manorial centre.