Constructed upon a volcanic rock, Deganwy Castle has been a fortified site for thousands of years. Rebuilt many times, its final form was a stone castle built by Henry III. However its strong defensive position was also its greatest weakness for it was difficult to resupply the garrison by sea when under siege.



The site of Deganwy Castle has revealed evidence of prehistoric, Iron Age and Romano-British occupation and would have been highly valued by all as a defendable location. This would have been particularly important given the exposed position of River Conwy where the easy access to the Irish Sea would have made the area an easy target for pirates and raiders. Occupying a large rock base that towers over the area, it offered a position of significant strength. The site consisted of two volcanic plugs which were connected by a series of timber defences and earthworks. It is possible the site was the seat of Maelgwyn Gwynedd, King of Gwynedd (circa-520–547). The dominant position wasn't always an advantage however - in AD 812 the castle was badly damaged when it was struck by lightning. Clearly rebuilt, the structure was destroyed by the Saxons in AD 822.


Robert of Rhuddlan built a castle at Deganwy around 1080. He was an important retainer of Hugh, Earl of Chester and in the 1070s had aggressively sought territorial acquisition at the expense of the native Welsh building a castle at Rhuddlan (Twt Hill). By the end of the decade he successfully exploited divisions amongst the Welsh to seize the cantrefs of Rhos and Rhufoniog (the former including Deganwy) and he raised the castle to control these new territories. He was staying at Deganwy Castle in July 1093 when he rode out to attack Welsh raiders and was killed in the subsequent skirmish; the Welsh raiders allegedly sailing off with his severed head attached to the mast of one of their ships.


The history of the castle in the hundred years after Robert of Rhuddlan’s death is a little vague but by the end of the twelfth century Deganwy was in Welsh hands for in 1191 it was described as a Royal Palace by Giraldus Cambrensis in the Itinerarium Cambriae. It remained a Welsh possession over the subsequent years aided by the policy of King John (1199-1216) to support Llywelyn ap Iorwerth, Prince of Gwynedd as a means of filling the power vacuum caused by his persecution of key Marcher Lords most notably William de Braose. But in 1211 Llywelyn himself defied John prompting an English army to invade. Whatever structure stood at Deganwy Castle at this time was pre-emptively destroyed by the Welsh to deny its use to the English. However, John's troubles with his Barons meant he could not sustain his army in Wales and Llywelyn was able to re-occupy the castle in 1213. He substantially rebuilt the castle and it clearly became one of his key facilities for in 1228 he imprisoned one of his sons there. Llywelyn's death in 1240 prompted the Welsh to once again destroy Deganwy Castle to prevent its use by the English.


Between 1245-54 Henry III rebuilt the castle into a substantial medieval fortification. The main part was constructed on the western summit which was crowned with a substantial round tower. A smaller, irregularly shaped structure known as Mansel's Tower was built on the eastern summit. A bailey was established between the two hilltops. A Royal Charter of 1252 formally created an adjacent borough but over the subsequent decade this new settlement was subject to frequent Welsh attacks. This culminated in the castle being besieged and captured by Llywelyn ap Gruffudd in 1263. His territorial gains were confirmed when Henry III sealed the Treaty of Montgomery (1267) recognising Llywelyn as overlord of Wales.


In 1272 Edward I became King. A veteran of the Barons War and a Crusader, relations with Llywelyn soon broke down in particular over his failure to pay homage. Two Wars of Welsh Independence followed with the second seeing all of northern Wales come under English control. Edward immediately commenced a large scale castle building programme to entrench English rule. The River Conwy was key to this but the site of Deganwy was not re-used. The 1263 siege had shown how vulnerable the hilltop location was and therefore Conwy Castle was built as a direct replacement - its waterfront location enabling easy resupply by sea. Building materials were robbed from Deganwy Castle for the new structure and what was left was allowed to drift into ruin.




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What's There?

Very little survives of Degwany Castle other than a few ditches and fragments of masonry most of which date from Henry III's castle built in the mid-thirteenth century. The core of the defences however was always the rocky hilltop and today the visitor can still appreciate the impressive defensive position. On a clear day there are excellent views of the surrounding area including Conwy Castle on the other side of the river.

Conwy Castle and Town. Following the Second War of Welsh Independence, Edward I built Conwy Castle as a direct replacement for Deganwy. As can been seen, the waterfront location enabled easy resupply by sea, even if the castle was besieged.

Masonry. Fragments of masonry of this once lavish castle remain but most of the stone was removed to support the construction of Conway Castle.

Getting There

Deganwy Castle is not sign-posted but can be found to the east of the A547 towering over Deganwy. There are a number of parking options including the Railway Station (Pay and Display) or All Saints Church (detailed below). A number of different paths led to the summit but none are paved so strong footwear is recommended.

Car Parking Option

LL31 9DZ

53.293842N 3.826859W

Deganwy Castle

No Postcode

53.298010N 3.828652W