The White Castle gets its name from the coat of white rendering that once covered it's walls. The castle was built by the Normans together with nearby Skenfrith Castle and Grosmont Castle as they won control over the North Gwent area.

The small twin towered gatehouse and the adjoining curtain walls and towers of the outer ward, were built during a massive refortification of the castle in the 1260s.

The uncertain political situation in Wales in the 1260s led to substantial refortification of White Castle. The curtain walls were strengthened by additional projecting towers equipped with arrow loops and a new entrance protected by a twin towered gatehouse was constructed.

The large defended outer ward was always part of the castle and was originally protected by a ditch and palisade before being walled. The outer ward acted as a kind of army base camp, with timber framed buildings against the walls.

In the 1260s the powerful twin towered gatehouse was part refortification of White Castle, built to protect the inner ward. The water filled moat was spanned by a fixed timber bridge with a drawbridge operated from the gatehouse.

The earliest part that still exist are the 12th century curtain walls of the inner ward.

At the heart of the castle lies the inner ward. It housed the principal accommodation of the great hall, kitchens, chapel, private chambers and well. Only the foundations remain of a square keep tower built around the early 12th century. At this time the rest of the castle defenses where still timber. Around 1185 stone curtain walls were built to enclose the inner ward and the tower was demolished.

View over inner ward towards twin towered gatehouse