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Deganwy Castle

A Scheduled Monument in Conwy, Conwy

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Latitude: 53.2979 / 53°17'52"N

Longitude: -3.8288 / 3°49'43"W

OS Eastings: 278214

OS Northings: 379440

OS Grid: SH782794

Mapcode National: GBR 1ZP9.WJ

Mapcode Global: WH654.5C0M

Entry Name: Deganwy Castle

Scheduled Date:

Source: Cadw

Source ID: 3395

Cadw Legacy ID: CN016

Schedule Class: Defence

Category: Castle

Period: Medieval

County: Conwy

Community: Conwy

Built-Up Area: Llandudno Junction

Traditional County: Caernarfonshire


The monument comprises the remains of Degannwy Castle which occupies a commanding position about 1/4 m E of the mouth of the River Conway. The fortifications occupy two precipitous hillocks separated by a saddle.

Few of the visible remains are likely to be earlier than the 13th century, but the site has a long history. Coins and a scrap of pottery indicate occupation during the Roman period. Late traditions make it the Llys of Maelgwn Gwynedd, and it is mentioned as ‘Arx Decantorum’ in 822. In c.1080 a castle was built here by Robert of Rhuddlan. The district was subsequently recovered by the Welsh, and in 1200 passed by inheritance to Llywelyn Fawr. The castle was destroyed in 1210 in the face of an English advance, refortified in timber by the Earl of Chester, and recaptured in 1213 by Llywelyn. In 1241 his son David once again destroyed the castle in preparation to resist an attack by Henry III, to whom the site was transferred as part of the peace terms. In 1244, the conflict was reopened, and the King ordered that the castle of ‘Gannok’ should be fortified, but the initial successes of the Welsh prevented much progress until he himself reached the site, where he remained from August to October of 1245. The castle was again attacked by Llywelyn ap Gruffydd in 1257, and was captured and probably finally destroyed in 1263.

Of the four or five periods of construction for which there is this documentary evidence, only two, both probably of the 13th century, can be identified on the site with any certainty. It is probable that the earlier works were all of earth, timber and dry stone, and those they were either reshaped or obliterated by the later structures. The rubble masonry is built of the local rhyolite forming the two hillocks; the fragments of dressed stone are of imported grit. The fortified area falls into three parts. The Donjon occupies the larger (W) hill, Mansell’s tower stands on the E hillock, and the Bailey occupies the saddle between.

Architectural Description: The Donjon of the mid-13th-century castle consisted of a polygonal enclosure wall about 4ft thick round the top of the hill. Near the NW angle are two latrine slots. The SW angle, at which the entrance lay, is destroyed. At the SE angle stood a round tower about 40ft in diameter with a simple roll moulding at its base - almost certainly the ‘tower of the castle’, built in 1247 and raised one storey in 1248. To the W of this lie the remains of a range of substantial buildings about 90ft by 30ft, including the King’s Hall, which was completed by 1250. At the E end of these and on a different orientation can be seen the angle of a rectangular building, perhaps part of the castle of 1213-41. To that period also may belong the revetment wall on the N side of the hill, which appears to be earlier than the main enclosure wall. The large quarry near the centre of the hill and the S end of a rectangular building E of it are ancient, but of uncertain period.

The Donjon was approached up a steep roadway rising from E to W along the S side of the hill, with a gate at each end. The track was bounded above by a revetted slope and below by a vertical revetment wall.

The S side of the Bailey is protected by a wall about 5ft thick with a ditch outside. Midway between the two hills are the remains of a strong gateway, with a passage about 8ft wide between a pair of D-shaped towers, each about 45ft by 30ft. Near the foot of the E hill a tower about 12ft square stood within the wall. Below it there appears to have been a latrine outlet, and higher up the hill the base of a small turret projects from the wall.

On the N side of the bailey the only surviving masonry is a short stub of walling just below the enclosure wall on the W hill, and a substantial fragment which seems to have been intended to form part of a gateway. Apart from these, the defences on this side are composed merely of a strong ditch and an earthen bank which seems never to have carried any masonry.

It was originally intended that the defences of the bailey should be completed in stone as on the S side. On August 23, 1250, instructions were sent to Alan la Zusch to raise Mansell’s tower by 12ft, to fortify the bailey of the castle between that tower and the donjon with stone and lime, and to make a barrier (incinctorium) outside the tower, two gates with two towers on each side in pairs, two suitable chambers above these towers, with fireplaces, and a chapel in the town of ‘Gannoc’ in honour of the Blessed Virgin. But in the Pipe Roll for 1250-4 payment is recorded for walling half the bailey and making one such gate. It seems clear that work on the N side was never more than started, and that very little further work was done on the fortifications.

Mansell’s Tower (on the E hill) now appears as a low wall, D-shaped in plan. It seems probable that the W side was originally closed. A platform a little below the top of the hill on the E side may be the remains of unfinished work for the ‘barrier’.

Outside the main enclosure are various earthworks. The gates on both sides of the bailey are approached by roadways slanting up the hillside. On the S of the W hill and on the N of the E hill are levelled platforms which seem to have carried rectangular buildings of uncertain age and purpose; and N of the bailey is a group of roughly rectangular enclosures sometimes associated with traces of long huts. These last may perhaps be the remains of the town, which received its charter in 1252 and from which a rent of 10 shillings is recorded in the Pipe Roll for 1250-5.

A millstone, 1ft 5ins in diameter and 3ins thick, having a central hole 3.5ins in diameter with two radial slots, was exposed just outside the S gate of the bailey in 1948. The construction of a horse mill was ordered in 1250.

The remains of the associated settlement are visible north and south of the castle as various bumps and hollows.

The monument is of national importance for its potential to enhance our knowledge of medieval defensive organisation and settlement. The site forms an important element within the wider medieval context and within the surrounding landscape. The site is well preserved and retains considerable archaeological potential. There is a strong probability of the presence of evidence relating to chronology, building techniques and functional detail.

Source: Cadw

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