The remains of White Castle, along with the close by Grosmont and Skenfrith Castles, were built on earlier Norman fortifications to dominate the border region between England and South Wales. The so-called ‘Three Castles’ were operated as a single defensive unit, known as the trilateral, under the control of an English Marcher Lord.

Originally named Llantilio Castle after the nearby village of Llantilio Crossenny, the impressive fortress coined the current name in the 13th century due to the white rendering covering the external walls. White Castle is the most heavily fortified of the triangle of the Welsh Marches fortifications and a classic example of mediaeval castle design, featuring numerous towers and high curtain walls perched high on a natural mound and surrounded by a deep water moat.