White Castle is one of the "three castles", along with Skenfrith and Grosmont, built to protect a strategic route into Wales. Founded by William fitz Osborn, it originally started life as a Norman motte and bailey fortification, shortly after the conquest of Britain. Between 1182AD and 1187AD, increased unrest in Wales led Henry II authorise the construction of a stone castle on the site, under the direction of Ralph de Grosmont. A defensive curtain wall was also erected a this time.

White Castle was granted to Hubert de Burgh by King John in 1201AD. Hubert was responsible for constructing the twin-towered gatehouse, although work was curtailed when he fell out of favour with the king, losing ownership of the castle for a short time. During this phase of building work, the castle was covered with a rendering of white plaster, from which it derives its name.

Following de Burgh's death, Henry III granted the three castles to his sons, Edmund and Edward. Around this time, Llywelyn ap Gruffud was leading a Welsh uprising, bringing his rebel armies within a few miles of White Castle. Accordingly, the fortification's military significance increased dramatically during this period.

In 1282, Llywelyn's uprising was crushed, and the strategic importance of White Castle diminished. White Castle always seems to have served as a military outpost rather than a home, and so it is unsurprising that during the years that followed, it gradually fell into decay. White Castle passed quietly out of history, and by the 16th Century, it lay derelict.

Today, White Castle is a picturesque ruin, occupying a particularly secluded and scenic location deep in Welsh border country. Surrounded by trees and enclosed by an un-drained moat, White Castle enjoys a wonderfully tranquil atmosphere. The ruins are remarkably complete, and this is easily the most splendid of the Three Castles. Highly recommended for a visit.