Rhuddlan Castle is in Northeast Denbighshire, Wales. Clwyd and the marshes formed a natural barrier to protect the coastal approach to mountainous heart of North Wales. Rhuddlan appears here in recorded history toward the end of the eighth century.

King Offa of Mercia reigned from 757 to 796 at which time the great dyke was built. It also bears his name. After King Offa's death, the English fought and won a battle at Rhuddlan. However, by 821 during Cenwulf's reign (he succeeded Offa) the English had not consolidated Rhuddlan and its manors under its rule.

In 921, King Edward the Elder built a fort at the mouth of the Clwyd, close to Rhuddlan, as a defense for the North Wales and Cheshire coastlines against the Scandinavians.

Gruffydd ap Llwelyn (a Foulke ancestor and High King of Wales) controlled Rhuddlan in 1063. He used it as a Royal Seat and base from which he plundered the English territories as far east as Oswestry and Wrexham. Earl Harold Godwine (Godwinson) drove Gruffydd out and burned his palace that same year.

The Conqueror granted Robert, a kinsman and lieutenant of Hugh d'Avaranches, earl of Chester, power over North Wales beyond the Clwyd. Robert used Rhuddlan as the base from which he set out to exploit and consolidate the holding entrusted to him by the king in Gwynedd. He was also a very important man in the Conqueror's ruling councils. Robert's father, Humphrey of Tilleul was in charge of the construction of the motte at Hastings which was built when the Normans landed in 1066 at Pevensey.

Robert's earthen mound now occupies the site of Gruffydd ap Llywelyn's palace. The outline of its bailey can still be traced in the adjoining fields.

Rhuddlan Castle and the town changed hands many times during the next two centuries as the warfare favored the Welsh and then the English and so on. Around the 1200's a part of the castle buildings were still constructed with wood. This was learned from a record of payments in 1241-1242 for timber to repair the wooden works. At this time they also built a wooden chapel in the castle where divine services could be celebrated.

Llywelyn ap Gruffydd was given, by King Henry III of England, an opportunity of authority over all lesser princes of Wales. In 1267 he earned recognition from the baron's leader Simon de Montfort and then from King Henry.

About 1277 under King Edward I, a new stronghold was built just to the northwest of the motte and built by Robert of Rhuddlan. A record shows payment for this on 14 September 1277 until March 1282. Master Bertram, an engineer of King Henry III was in control of this work. Master James of St. George later became the master of the kings works in Wales. He is regarded as the architect of Rhuddlan castle as he saw it through to its completion.

The castle is built in such a way that it can be strongly defended from an inner ward which is diamond shaped with a single tower on each of the north and south angles. It is surrounded by an outer ward. There are other buildings such as a great hall, kitchens, private apartments and a chapel. The buildings of the outer ward consist of a granary, stables, a smithy, the treasure and a goldsmith's workshop. However, there isn't much of these building to see now.

There was a Welsh uprising by Glyndwr in 1400 in which the town was badly damaged. However, the castle was not. During the Civil War, Rhuddlan was in the hands of the Royalists until they were forced out in 1646. Then it was partially demolished to prevent further use in 1648.