At the beginning of the 12th century, Wales consisted of numerous independent principalities and kingdoms, which were often in conflict with each other. The Anglo-Norman kings did not directly engage in the conquest of Welsh lands, leaving this task to the Lords of Marches, border territorial units with extensive autonomy. As part of this gradual conquest of southern Wales, in 1107 king Henry I gave the Gower peninsula to Henry de Beaumont, Earl of Warwick, who invaded the area and immediately built a castle in Swansea. He also distributed the land on the peninsula to his supporters, giving the area around Mumbles to William de Londres, a Norman knight who was also the owner of the Ogmore castle. Shortly after receiving new lands, around 1106, William built the Oystermouth Castle on the hill above Swansea Bay. This original building was probably a timber – earth ringwork.
In 1116, Gruffydd ap Rhys raided the Gower peninsula and burnt the castle. The Normans rebuilt it, but in 1136 Gower was again attacked by the Welsh, this time by Hwyel ap Maredudd, and it is possible that Oystermouth was destroyed again. Subsequent attacks on the peninsula, this time Rhys from Dehebarth, took place in 1189 and 1192, although the castle survived in both cases. In 1203, the English king John granted Gower to John de Braose, but the Oystermouth Castle remained the property of the Londres family. The male line of this family ended in 1215, and the castle passed into the hands of William de Braose. At about the same time, the Oystermouth Castle was again attacked by the Welsh under the command of Rhys Grug and Rhys Leunan, the allies of prince Llywelyn ap Iorwerth. In 1220, the Welsh were eventually expelled from the peninsula, and Henry III returned the Gower barony to John de Braose, who rebuilt the castles at Swansea and Oystermouth, although in 1257 peninsula was ravaged by the Llywelyn ap Gruffydd.
The de Braose family was one of the main Anglo-Norman families, and Oystermouth became their main residence in the 13th century. During their rule, the castle was rebuilt into a stone stronghold. William, Lord of Gower and second Baron Braose, was a powerful magnate in the court of Edward I who hosted the king for two days at Oystermouth in 1284. He served Edward in both the Welsh and Scottish Wars, and his significant achievement was the capture of the Welsh rebel William Cragh and participation in the victorious Battle of Falkirk in 1298. At the beginning of the 14th century, he enlarged the castle in Oystermouth with a building of the chapel.
In 1331, the castle passed on to John de Mowbray, who was the first owner who live in a different place than Oystermouth. In 1354 the Mowbrays lost the castle due to legal battles to the Beauchamp family, but regained it in 1397. The subsequent owners of the castle from the Herbert family were also not very interested in it. The stronghold declined, and this is probably why it played a minor role in the Welsh rebellion of Owain Glyndŵr, which occupied the Gower peninsula between 1403 and 1405. Over the following centuries, the castle frequently changed owners, but none of them undertook its rebuilding.
The castle was built on a hill, sloping on the eastern side towards the waters of Swansea Bay. It received the form of a polygon in the plan, with defensive walls narrowing towards the south-east, where there was an entrance to the inner ward. It was secured by a gatehouse from the second half of the 13th century, consisting of two flanking horseshoe towers with a diameter of about 7 meters. Compared to other similar structures from this period (eg Caerphilly), the gate at Oystermouth was simpler and less fortified. It had two sets of doors and one portcullis, but no rooms on the sides of the passage. The rooms on the first floor of the gate were accessible through entrances from the courtyard and a spiral staircase embedded in the thickness of the wall.
The oldest stone building of the castle was a quadrilateral keep with dimensions of 16.8 x 10 meters, with walls 1.7 meters thick, located on a rocky elevation of the area. In the 13th century, it was expanded from the north, which more than doubled its size and provided the main living and representative rooms in the castle. The original entrance to it was at the level of the first floor, but already in the 13th century a new entrance was pierced in the ground floor, around which a vestibule was later erected. The communication between the floors was provided by a staircase in the north-west part of the keep. The main living quarters were on the first floor. The representative great hall was located in the southern part, and the private room (solar) on the north side. The ground floor was vaulted and probably had an auxiliary character. The hall could be covered with an open roof truss. With the addition of buildings around the keep, new doors were introduced to improve communication. In this way, it was possible to easily go to the north-west range and the chapel on the south-east side.
The north-west wing from the mid-13th century filled the entire corner of the castle with slightly thinner walls. It was 16 meters long and had three storeys, the lowest of which was already vaulted when the building was erected, and the higher as a result of later transformations. The building housed, inter alia, a prison and garrison rooms. On the south side, they were adjacent to two other 13th-century buildings, located in one line at the western curtain of the wall.
At the beginning of the 14th century, the chapel building was fitted to the south-eastern corner of the keep. From the side of the courtyard, this monumental building was provided with three four-sided projections and two more on the north side. The largest of them, in the form of a slender turret, was the south-west one, with a spiral staircase inside. The south-eastern one housed the latrines. The interior of the building consisted of a well-lit chamber with a fireplace and latrine on the first floor. The ground floor probably played an economic role, and the chapel itself was on the second floor. It was lit from the courtyard side with two large pointed windows with traceries. It contained two opposite, vaulted niches in the north and south walls, supporting the chimneys. In the southern recess, fragments of wall polychrome have been preserved, while in the south-eastern corner the piscina was placed.
The remaining buildings in the castle were erected in the late Middle Ages. It was a rectangular building at the eastern defensive wall, reaching one of the shorter sides of the gatehouse, and an oblong, rectangular building of the castle’s kitchen, occupying the south-west part of the courtyard.
The castle has survived to modern times in a state of well-preserved ruin with a full circumference of defensive walls and walls of all buildings inside. The most noteworthy lack are the flanking gate towers which no longer exist. Only the holes on the floor beams are visible in their back walls. The castle has recently undergone a thorough renovation, thanks to which all its parts have been made available to the public. Unfortunately, the opportunity was not without the insertion of modernist glass – concrete – metal elements biting the historic substance. The castle is open from April 1 to September 30 from 11:00 to 17:00.
Kenyon J., The medieval castles of Wales, Cardiff 2010.
Lindsay E., The castles of Wales, London 1998.
Salter M., The castles of Gwent, Glamorgan & Gower, Malvern 2002.
Website castlesfortsbattles.co.uk, Oystermouth castle.