Known as one of the “Three Castles”, there has been a defensive structure at the site since the late eleventh century.
The term “The Three Castles” is used to collectively describe White Castle, Skenfrith Castle and Grosmont Castle, all of which are located in the Monnow Valley in south Wales in modern-day Monmouthshire.
The River Monnow valley was an important route between Hereford and South Wales in mediæval times, due to its position as an area of relatively open land, which provided a break between the river cliffs of the Wye Valley to the south, and the hills around Abergavenny to the west. The Three Castles are usually grouped together by historians because for almost their entire history they were part of a block of territory under the control of a single lord.
All three sites have evidence for early Norman earthworks, possibly built by William fitz Osbern, who was made Earl of Hereford by William the Conqueror a few months after the Norman Conquest of England in 1066. From his castles at Monmouth and Chepstow, William was the first Norman lord to conquer central and eastern Monmouthshire, including the future sites for the Three Castles. The defenses raised at this time would have been of earth and timber, probably in the classic Norman motte-and-bailey style.
Fitz Osbern died in 1071, and his lands were forfeited to the Crown after his son Roger de Breteuil was involved in a rebellion against King William in 1075. In order to prevent the rise of such a powerful magnate, the King divided up this strategically important territory – the only time in their active history that the Three Castles were owned separately. They were reunited by King Stephen before July 1137 and would remain a single lordship until the nineteenth century.
There is little evidence of building activity at any of the castles until the late twelfth century, when they were fortified by Ralph of Grosmont, a Royal official who supervised building work for the King in Hereford. Ralph was responsible for building the towering curtain wall around the inner ward in 1185-87. The castles were later completely overhauled by Hubert de Burgh, who was granted lordship of the Three Castles by King John in 1201. Control of the Three Castles was briefly granted to William de Braose in 1205, when Hubert was a prisoner of Philip Augustus, the King of France, but William de Braose quickly fell out of favour, and by 1207 King John had forced him into ruin. Hubert de Burgh returned to power, and was appointed Justiciar in 1215.
From his time fighting in France Hubert had a knowledge of the latest in military architecture, and in the years after 1219 he was a prosperous lord who had great influence with the young King Henry III. He rebuilt Skenfrith between 1219 and 1222 and Grosmont between 1224 and 1226in stone, adding domestic apartments to both castles, so that they could be used as lordly residences. He held the Three Castles until 1239, although they were briefly taken from him after he fell out of Royal favour in 1232 (they were returned after his reconciliation to the King two years later). Hubert first added four round towers to the inner ward of White Castle in the period 1229 to 1232. One pair of these made the great gatehouse. After his return to royal favour in 1234 he added to the two great D-shaped towers to the inner ward and built the masonry outer ward. He was probably also responsible for demolishing the original square Norman tower keep. On the king resuming the castles in 1239 Hubert was said by Matthew Paris to have spent a small fortune on their building.
After Hubert de Burgh, the Three Castles were held in Royal hands, and in 1254 Henry III granted them to his eldest son, the future Edward I. In the 1260s the southern March was threatened by the Welsh prince Llewelyn ap Gruffudd, who annexed the lordship of Brecon, and attacked nearby Abergavenny. Gilbert Talbot was appointed Constable of the Three Castles, and ordered to garrison them ‘at whatever cost’. Although Llewelyn’s attack on Abergavenny failed, the Treaty of Montgomery in 1267 recognized his southern conquests, and he was considered a significant threat.
1267 saw the Three Castles being granted to Edward’s younger brother Edmund, Earl of Lancaster. Although the Welsh threat was soon subdued with the death of Llywelyn in 1282, the Three Castles were used as residences and centres for local authority. The castles passed down through the Earls of Lancaster until the death of Henry of Grosmont, Duke of Lancaster, whose daughter Blanche married John of Gaunt, son of Edward III. John of Gaunt was made Duke of Lancaster in 1364, and the Three Castles would remain part of the Duchy of Lancaster until 1825. John and Blanche’s son, Henry of Bolingbroke, deposed Richard II in 1399 and became King as Henry IV, at which time the Three Castles also became Royal possessions once more.
Although the Three Castles briefly saw action during the rebellion of Owain Glyndŵr in 1404-05, they never again played a major role in military affairs. Henry VI carried out repairs to White Castle and Skenfrith Castle in the mid fifteenth century, but by 1538 the castles were abandoned, and ruinous. In 1825 the Duchy of Lancaster sold the castles to the duke of Beaufort, whose estate divided them and sold each to different local landowners in 1902. White Castle was given to the State in 1922, followed by Grosmont in 1923. Skenfrith passed through several hands before being given to the National Trust. All three castles are now conserved and maintained by Cadw, and are open to the public.
The earliest castle at this site consisted of two earthworks – the pear shaped inner ward with a surrounding water-filled moat, and a crescent shaped outer bailey to the south known as the hornwork. To the north of the inner ward was a large area enclosed by a defensive bank, which may have been used for armies in the field to camp in safety, without fear of a surprise attack.
The earliest buildings and walls were almost certainly built of wood, although a square stone keep was added sometime before the stewardship of Ralph of Grosmont, who recorded an expenditure on “the dwelling in the tower of Llantilio” in the Pipe Rolls of 1186-87, implying that structure was already present. Further monies spent at the site were most likely for the construction of a stone curtain wall around the inner ward.
Like its fellow Monnow Valley strongholds, White Castle was significantly altered by Hubert de Burgh as has been described above. The orientation of the castle shifted, with entry no longer through the southern hornwork. Instead, a new twin-towered gatehouse was built at the northern end of the inner ward. Wooden drawbridges would have controlled access from both the north and the south of the castle. Within the inner ward there would have been residences, great hall, a chapel, kitchen and brewhouse. Hubert's work here can be compared to Montgomery Castle which he also held and helped design between 1223 and 1232.
The hornwork, now at the rear of the castle, was maintained as a defense for a small rear postern gate. The northern enclosure, previously defended by an earthwork, was built into a large outer bailey, with four projecting towers and a gatehouse on its eastern corner. Geophysical evidence suggests that there were small timber buildings within the walls of the outer ward, as well one large building, thought to be used as a barn.
The castle today stands in partial ruin, although there have been few significant losses to time. The stone walls and towers of the inner and outer ward still stand, although their inner floors are missing, as are portions of the upper level of the walls. A modern wooden bridge spans the moat between the inner and outer ward, and within one tower of the inner gatehouse the stairwell has been restored, allowing access to the top of the tower, and a commanding view of the surrounding countryside.
The castle is maintained by Cadw, and access is controlled during the summer months. The rest of the year the castle is an open site, and may be visited at any reasonable time of day. White Castle is located 1 mile north of the village of Llantilio Crossenny, along the B4233 between Monmouth and Abergavenny.