Like Builth Wells, Hay actually has two castles. It is likely that Hay was first fortified by William Fitz Osbern during his penetration of south-east Wales during the summer of 1070. Over subsequent generations, the castles passed into the hands of many notorious Norman families including the Neufmarches, the Braoses and the Bohuns.
The remains of this fortress now lie beneath the current castle ruins and mansion. Without a doubt, this was the castle recorded as 'castello de haia' that surrendered to Miles Gloucester in 1121 along with Bernard Neudmarche's daughter. In 1165, the last of Miles Gloucester's male descendants was killed in a nearby battle. Hay-on-Wye Castle was handed to the care of the notoriously ruthless William de Braose. Under the Braose rulership, the castle seems to have been developed, and it is likely that the gatehouse which now stands beside the keep dates from this period. A popular historic novel, The Lady of Hay by Barbara Erskine, vividly describes life at the castle and within the de Braose Family during this period. The last Braose of Brecon was hanged by Llywelyn ap Iorwerth in 1230, and the lordship of Hay-on-Wye passed to the Bohun family.
Llywelyn and his forces continued to ravage the lands of the Bohuns, and during one such attach in 1231, the town of Hay-on-Wye was badly burned, though the castle survived. The castle continued to see service and changed hands three times - at one point it was surrendered into the hands of the famous Simon de Montfort. The conquest of Wales by Edward I finally brought more peaceful times to this border town, but just over a century later both the town and castle came under attack once more by Welsh forces, when in 1401 Owain Glyndwr and his legions swept through the region.
During the later medieval period, the castle passed into the hands of the earls of Stafford, who were to become the unlucky dukes of Buckingham during the Ward of the Roses. In the 1660s James Boyle of Hereford began the construction of a new mansion on the north side of the castle, and demolished most of the curtain wall to improve the views. The mansion continues to be used today - not surprisingly for Hay, as a second hand bookstore.
The other castle remains are located close to St Mary's Church in Hay. It is a small but well-preserved motte. It was probably constructed by William Revel, a knight in the household of Bernard de Neufmarche. It may later have become the seat for the commote of Melinog, but has no further recorded history.
Hay was put on the map on April 1 1977 when book enthusiast Richard George William Pitt Booth declared Hay-on-Wye to be an independent kingdom, and nominated himself its monarch. Since then, Hay has developed a healthy tourism industry based on literary interests.