Castle of the Week 98 – Caerphilly Castle

Caerphilly Castle is one of the great medieval castles, little changed from the 14th century. Covering 30 acres, it’s the largest castle in Britain after Windsor and it was also the first truly concentric castle to be built in Britain.

Romans built the first fort at Caerphilly in about 75 AD with 500 soldiers guarding one of the main legionary roads. However after the Romans left 50 years later, the site was unoccupied for a thousand years. It’s believed an earth & timber castle was built there either by the Normans or Welsh in the 12th century but no records or earthworks remain.

In the late 13th century, the area of Caerphilly was owned by Gilbert de Clare, a Norman lord. He sided with the English barons with the future Edward I against Simon de Montfort and, after de Montfort was killed, took part in a siege of his castle at Kenilworth. He was very impressed with Kenilworth’s defences, particularly the moat and lake. He had 9 months to examine the defences before the siege ended and he took the ideas back home to Caerphilly where he got permission from Henry III to start building a castle to defend the area after a dispute with Llywelyn ap Gruffudd.

The castle was to be concentric and massive, surrounded by large water defences. De Clare flooded a valley, making a lake a third of an acre in size, with the castle built on 3 artificial islands. The eastern island was a great fortified dam, the westernmost contained a walled redout, both protecting the central island which housed the main castle buildings. Llewelyn saw the castle as a direct threat to his authority and, late in 1270, he attacked and burnt some of the fortifications down whilst they were still being built. De Clare continued the building and, when Llewelyn attacked again in Autumn 1271, he was defeated. In 1277 the outer gatehouses were finished and other work was carried on over the next 50 years.

The concentric arrangement was flexible with rapid access to any part of the castle by wall passages and walks. The towers and gatehouses could be shut off and defended separately and most parts could be enclosed with portcullises. The outer wall was a low curtain wall with large bastions on the corners and gatehouses on the east and west sides approached by drawbridges. After a narrow strip of land came the much stronger and higher inner curtain wall with circular corner towers and 2 large strong gatehouses. Lakes on the south and north side blocked attack from those directions, the dams being a great achievement in medieval times. The magnificent great hall and state apartments were on the south side of the inner ward.

Seven years later, after Llywelyn was killed, Caerphilly was used as the administration centre for the de Clare estates in Glamorgan. Gilbert’s son, also Gilbert, was killed, childless, at Bannockburn so the castle and lands came under royal control until their future was decided. In 1316, after the royal guardians had provoked a Welsh revolt in the area, Llywelyn Bren led an army of 10,000 men to attack the castle. A drawbridge was burnt, but otherwise there was no damage to the castle.

In 1317 the de Clare lands were divided between Gilbert’s 3 younger sisters. The oldest was married to Hugh Despenser, a greedy man and a favourite of Edward II. He wasn’t content with the share he had chosen so he set out to take the other two portions as well. He was hated by the March Lords of south Wales because of his cruelty and, in 1321, they burnt and destroyed much of his property. However, with the king’s support, the lords were defeated. He expanded his lands in south Wales until he controlled all the land between Chepstow & Pembroke.

In September 1326 a small force, led by Roger Mortimer and Edward II’s estranged wife, Isabella, landed from France. The king and Despenser fled to Caerphilly Castle which was besieged for four months, although Edward and Despenser had already escaped. It surrendered in 1327 and the two men were eventually captured, Despenser being executed and Edward II being forced to abdicate. The castle was threatened by Owain Glyndwr in the early 15th century and probably yielded to him.

That was the end of the castle’s great days and it fell into ruin. In the late 16th century, a local man was given permission to use stone from the castle to build his new house. Others followed. It played some part in the Civil War. Although the castle itself was unusable, an earthwork redoubt was built in the north-west. The ‘leaning’ tower is thought to have started leaning at that time after a botched effort at demolition by Cromwell’s soldiers. It still stands 10 degrees from the perperdicular. By the 18th century the lakes were dry.

In the 1870s there was a move to protect it from further ruin and the great hall was re-roofed. In the 1930s, the marquess of Bute undertook to restore it. He rebuilt many of the collapsed buildings and walls so that when it was taken over by the State in 1950, all that was left to do was the reflooding of the lakes and the restoration of the great hall.

Write-up provided by GillB. All pictures courtesy of Castle Xplorer.