Dyserth Castle () is a castle site in Denbighshire in the country of Wales. It is a scheduled monument protected ancient borough on a ridge north of the village of Dyserth. It was the last castle of the British fortified defences on the Clwydian hill range in the Middle Ages. The nearby village of Dyserth got its name from the castle. History Dyserth Castle has been known also as Castell Diserth, Castle de Rupe, Castle of the Rock, Caerfaelan, Carregfaelan, Castell-y-Garrec, Dincolyn, Castell y Ffailon, and Castell Cerri. It is on a high rock summit of carboniferous limestone less than a mile from its namesake village. Excavation of the site shows four periods of fortified occupation – Neolithic, Bronze Age, Romano-British and Middle ages. There are local stories of a "Castell Dincolyn" at this hill of pre-Norman times. The Welsh prince Llywelyn the Great died in 1240, and after his death the English extended their authority into Wales as far north as the River Conwy. This was from the result of three military campaigns to expand the royal lands of the County of Chester. To confirm their control of the territory the English then began the building of new castles and rebuilding of certain older castles including Rhuddlan Castle and Deganwy Castle. Dyserth Castle was one of those castles, and was intended to replace the original Old Rhuddlan castle at Twthill and to supplement Deganwy Castle. Dyserth Castle has an unclear recorded history for its beginning foundations. A castle was thought to have been begun in 1238 somewhere close to the present site. This first castle was unsuitable, and either taken down completely or reinforced in 1241 by Henry III to become an English fortified castle. Sir Robert Pounderling, an English knight, was constable of the castle from 1241 to 1263. There is a story that he had one of his eyes poked out by a Welshman during a tournament at the castle. Pounderling was challenged again in another tournament by the Welshman, but declined – he didn't want the other eye poked out! Einion, son of Rhirid Flaidd, was killed at the siege of Dyserth Castle in 1263. A cross called "Bryn Einion" was erected on the spot of his death. The shaft, at one time a part of the stile in the Dyserth churchyard, bears an inscription of strange lines and letters. According to a manuscript by Dafydd