White Castle is the largest of the Three Castles of northeast Monmouthshire - a trio of forts, also including Grosmont and Skenfrith, that were built by the first Normans then greatly expanded by nobleman Hubert de Burgh (ca1170-1243) towards the start of the 13th century. The three form a defensive triangle, each separated by about four miles, in undulating land near the River Monnow, originally part of England but now in Wales. White is situated on a hill high above the River Trothy, a tributary of the Monnow, in what has always been a remote, rural region, not close to any major settlements. The nearest village, Llantillo Crossenny, is just over one mile southeast, and the fort was initially known as Llantillo Castle, receiving its new name soon after the 13th century expansion, apparently on account of whitewash used on the walls.
The central section of the castle, the inner ward, is enclosed by a curtain wall approximately oval in outline, supported by six towers, two of which border the gatehouse, on the north side. All is surrounded by a moat, and the entrance, originally a wooden drawbridge, now a metal replacement, is from the outer ward, a subsidiary walled enclosure which is accessed from an east-facing outer gate. The upper floor of the gatehouse survives, but the towers are empty, and of the various buildings inside the inner ward, including a hall and kitchen, only on low wall fragments remain, yet overall the castle is still impressive, on account of its relatively large size, the deep moat, still mostly full of water, and for the peaceful, remote setting.
White Castle is reached by several un-designated country roads, between the B4521 to the north and the B4233 to the south, and lies on a flat-topped hill, adjoining Upper White Castle Farm. The short approach road ends at a parking area with space for about six vehicles. Entrance to the castle is from the east, past a cabin used by Cadw during the summer months; at other times of the year the place is unstaffed and entrance is unrestricted. Two trails continue from the end of the track; to the west is Offa's Dyke Path, a long-distance route that crosses all of Wales, between Prestatyn and Chepstow, while to the north is the Three Castles Walk, a 20 mile circuit that also visits Grosmont and Skenfrith. To the south both routes run along the road a short distance before diverging.
The Outer Ward
The path from the parking area first crosses the lower ditch that surrounds the walls of the outer ward, and would once have been shallowly filled with water, and passes through the remains of the outer gate - this is missing the front and back walls, each of which originally contained a gate, but still has most of the thicker side walls. These retain several arrowslits and other openings. Beyond the gatehouse lies an irregularly shaped grassy enclosure, the outer ward, which housed various non-permanent structures including tents and wooden buildings. The ward is enclosed on three sides by walls, today varying in height from 3 feet (to the east), to over 20 feet, and incorporating four, two storey towers; a circular tower at the northeast corner, two half round towers and one square tower. This latter is the largest, set in the middle of the west wall, and its walls contain three neatly constructed windows, looking out in different directions. The south side of the outer ward borders the moat, which today is filled with deep water on the west side but is usually dry and overgrown to the east and south.
The bridge from the outer court enters the north side of the castle through the front gatehouse, an arched corridor, originally guarded by two portcullises, between a pair of four story towers (basement, ground floor and two upper floors). The intermediate floors of the eastern tower have been replaced, together with stairs that allow visitors to climb to the top, however these are only accessible when Cadw staff are present. The interior of the east gatehouse tower is completely empty. Inside the castle are low walls from the hall, the solar room (sleeping quarters) and chapel along the east side, plus a well, and a kitchen and brewhouse on the west side. To the south are about half of the foundations of the 12th century keep, the first stone component of the castle, which was demolished to make way for the curtain wall. Also along the southern wall is a rear (postern) gate, once the main entrance that connected with another external, fortified area (the hornwork, or outer bailey), which like the castle itself was surrounded by water. The castle has two more (D-shaped) towers at the south corners, and a further two, round in outline, along the east and west sides - all four have walls with different levels of completeness, and they lack any internal structures.
Like Skenfrith and Grosmont, White Castle began as a motte and bailey fort, erected shortly after the Norman invasion, and was used to patrol this relatively open land, along an important travel route between south Wales and the English Midlands. The first stone structures were constructed almost a hundred years later, in part under the direction of Ralph de Grosmont; these were the keep and (later) the curtain walls. Additions by Hubert de Burgh in the next century included the gatehouse, the other four towers, the replacement south wall, and all of the outer ward. Ownership of White Castle reverted to the crown around 1250, and it remainded in military use until the end of the Welsh insurgencies following the death of Llewelyn the Great in 1282. The place was subsequently used as a residence, for at least the next two centuries, and was then owned by the Dukes of Lancaster, who descended from Edmund, a younger brother of Edward I, but the fort had become partly ruined by the start of the 16th century.