Caerphilly Castle
Historic Overview
Caerphilly Castle (Castell Caerffili) is a Medieval fortification in Caerphilly, South Wales. The castle was constructed by Gilbert de Clare in the 13th century as part of his campaign to maintain control of Glamorgan during Anglo-Norman expansion. The Romans built an auxiliary fort here as early as 75 AD, but it was abandoned by the 2nd century and for the next one thousand years, the site remained sparsely populated. The castle is surrounded by extensive artificial lakes and considered to have the most elaborate water defences in Britain. It is the largest castle in Wales, and second largest in the UK after Windsor Castle. Works on the castle began in 1268 under the orders of De Clare and was completed three years later at a considerable cost. The building project was opposed by his Welsh rival, Llewelyn ap Gruffudd, leading to the site being burnt in 1270 and taken over by royal officials under Henry III in 1271, namely Roger de Meyland and Godfrey Giffard. Despite these conflicts, the castle was successfully completed by De Clare when he re-seized the region.
Llewelyn's power gradually declined whilst Edward I invaded Wales following a dispute in 1277. Five years later, his second campaign would result in Llewelyn's death and the collapse of Welsh rule. Local disputes continued and following uproar between de Clare and the Earl of Hereford in 1290, the castle was temporarily seized by the King. The castle was later attacked during the Madog ap Llewelyn revolt of 1294. Morgan ap Maredudd, who led the local uprising burned half of the town but failed to take the castle. Edward I stopped the rivalry, allowing De Clare's forces to attack Morgan's and regain the region. Gilbert de Clare died soon after in 1295, leaving the castle in good condition and associated with the well-established small town of Caerphilly and with it, a large deer park in the nearby Aber Valley.
De Clare's son inherited the castle in the early 14th century but died shortly after. The family's lands were placed under the control of the crown, but the Llewelyn Bren revolt of 1316 resulted in the castle being attacked. The castle withstood their efforts, but the town was destroyed. Eleanor de Clare acquired the castle and married Hugh de Despenser, a close ally of the King. During the overthrow of Edward II in 1326-27, by his wife Isabella of France, Hugh and the King fled. When they abandoned the castle, Sir John de Felton, Hugh's son and their garrison protected the castle. They surrendered under the condition of a pardon, however le Despenser had already been executed.
In 1400, the Glyndwr Rising broke out, but the castle survived intact. The castle was passed to Isabel le Despenser, who with her second husband Richard Beauchamp, heavily invested in the castle. They conducted extensive repairs and restorations to establish a suitable residence. The castle was then passed to Richard Neville in 1449 and later to Jasper Tudor, the Earl of Pembroke, in 1486. In the late 15th century, it fell into major decline and by the 16th century, the lakes were drained away and the castle walls robbed of their stone. During this time, it was recorded by John Leland as a ruin, surrounded by marshland. However, Henry Herbert, Earl of Pembroke, still used the castle as a manorial court. The castle was leased to Thomas Lewis who stripped the castle of various building materials, causing further significant damage.
By the 18th century, most of the towers had collapsed. However, it is unclear whether this was a result of conflict or damage caused by the retreat of the moat. In 1776, John Stuart, the 1st Marquess of Bute acquired the property and undertook extensive restoration works. His great grandson John Crichton-Stuart, the 3rd Marquess had the site surveyed by architect William Frame, who had the grand hall re-roofed in the late 19th century. The castle underwent restoration in 1928 by John Crichton-Stuart, the 4th Marquess. The stonework was carefully repaired and the inner gatehouse rebuilt, along with several other towers. Landscaping was carried out, and after several decades, the local houses encroaching the castle view were eventually demolished. In 1950, John Crichton-Stuart, the 5th Marquess gave Caerphilly castle and its grounds to the state and the water defences were re-flooded.
Architectural Overview
Caerphilly Castle lies in a basin of the Rhymney Valley, alongside the river and at the heart of a network of paths and roads, and near a former Roman fort. The castle was built on what became a central island, surrounded by artificial lakes. Water rather than height provided its primary defence. Ditches were cut, wooden palisades erected, and water barriers created as the first line of protection. The dams were further fortified and an island to the west provided additional protection. Estimates suggest that approximately £19k was spent on its construction, a great sum for the time. Whilst the architect and exact cost of construction are unknown, it’s suggested to be on par with those of Conwy or Caernarfon. The core of the castle was built of sandstone, on a quadrangle plan with four cylindrical towers, a great walled court, and huge twin-towered gatehouses. The court has a concentric walled platform that rises from the lakes, held back by a fortified embankment. Originally the gatehouse would have been reached over a sequence of two drawbridges, linked by an intervening tower that has since been destroyed.
To the north side of the gatehouse was the North Dam, protected by three substantial towers, which may have supported the castle's stables. Despite damage, the dam still holds back the North Lake. The remains of the castle corn mill, originally powered by water from the dam still survive. The dam ended in Felton's Tower, a square fortification designed to protect the sluice-gates regulating the water levels of the dam, and the South Gatehouse (also called Giffard's Tower) was originally accessed via a drawbridge, which led into the town. Two huge towers flanked the gatehouse on either side of an entrance that was protected by portcullises and murder-holes. The substantial size of the gatehouse allowed it to serve as both a living quarter for the constable and his family, and line of defence.
The Great Hall was constructed in the 14th century, and would have been subdivided with wooden screens, displayed colourful decorations, rich detailed carving and warmed by a large central fireplace. Some carved medieval corbels in the shape of male and female heads survive in the hall today, possibly depicting the royal court in the 1320’s, including Edward II, Isabella of France, Hugh Despenser and Eleanor de Clare. To the east of the Great Hall was the castle chapel, positioned above the buttery and pantry. On the west side of the hall were the castle's private apartments, two solar blocks with luxurious fittings.
In 1416, Isabella Le Despenser and her second husband invested heavily in the castle, carrying out repairs and making it the main residence in the region. In the late 15th century, it was taken over by Jasper Tudor, Earl of Pembroke. From that moment, the stronghold began to decline. By the first half of the 16th century, it was already in ruin, and the surrounding water was transformed into swamps. Although one of the towers remained in use as a prison for local criminals. In 1593, the castle was rented by Thomas Lewis, who began its demolition to enlarge his home. When the English Civil War broke out in 1642, an earthwork (or small fort) was built near Caerphilly Castle. It is uncertain whether it was raised by the royalist forces or by the army of the Parliament. In the 18th century, several towers collapsed due to damage incurred over time.
At the end of the 18th century, protection measures were put in place by the 1st Marquess of Bute who owned the castle ruins at the time. The work was continued by his great-grandson who renovated the great hall in the 1870’s. The 4th Marquess went on to commission a comprehensive castle renovation project between 1928 and 1939. Works on re-flooding the area around the castle were also started and the houses covering the monument were demolished. In 1950, the 5th Marquess of Bute donated the Caerphilly castle to the state.
Modern Legacy
During the 1970's, a bronze dagger was found on site. Excavations in 2001 recovered 13th - 14th century pottery sherds. Between 2002 and 2008, several features were uncovered including a set of limestone slab steps, a considerable amount of intact original flooring and sealed clay and mortar suggesting that the tower was used as a brewhouse. In 2019, an excavation in the great hall encountered further 14th century pottery. Whilst works in 2021 revealed a pavement of Pennant flag stones, an undated stone structure, and old wall footings. An evaluation the same year encountered a deposit of blacksmithing waste, residual Romano-British grey ware, and medieval pottery, primarily glazed and un-glazed Vale ware.
In 1963, Caerphilly castle was placed within the care of Cadw, which now manages the site as a tourist attraction. It is protected as a Scheduled Monument (GM002) and a Grade I Listed Building (Cadw ref. 13539). It has become a space where schools and community groups can immerse themselves in the history of Wales. The castle houses new interactive exhibits that bring to life some of the most important people in 13th century Wales. Four replica siege engines and dragons have also been placed on display. Today, the Great Hall is available for wedding ceremonies, and several episodes of the long-running British television show, Doctor Who, have also been filmed on site.
Location
NGR ST1552787068
Selected Bibliography
Britannica, The Editors of Encyclopaedia. (2023). "Caerphilly". Encyclopaedia Britannica.
Cadw. (2023). Caerphilly Castle. Available at: Caerphilly Castle | Cadw (Accessed: 17 Sept. 2025).
Cartwright, M. (2020). Caerphilly Castle. World History Encyclopaedia.
Coflein. (2025). Caerphilly Castle. NPRN 94497. RCAHMW. Available at: https://coflein.gov.uk/en/site/94497/ (Accessed: 17 Sept. 2025).
Davey, J. and Moreno, J. (2023). Archaeological Watching Brief Report: Caerphilly Castle Moat Banks. Archaeology Wales.
Davis, P. (2017). Caerphilly Castle. The Gatehouse.
Glass, E. (2022). Caerphilly Castle Moat Banks. Archaeology Wales.
Heneb. (2025). Caerphilly Castle. PRN 00696m. Archwilio. Available at: Archwilio (Accessed: 17 Sept. 2025).
Johnson, L. (2021). Caerphilly Castle. History Hit.
Lewis, R. (2018). Caerphilly Castle Maze and Dragon's Lair. Heritage Impact Assessment. Black Mountains Archaeology Ltd. Report 128.
Moore, D. (2020). The Great Hall, Caerphilly Castle, Caerphilly. Archaeology Wales.
Prizeman, O. E. C., et al. (2017). Modelling from the past: The Leaning Southwest Tower of Caerphilly Castle 1539-2015. ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol. 4. 26th International CIPA Symposium. Ottawa: Canada.
Windsor, K. (2023). A Brief History of Caerphilly Castle.
Cite this Work
Harvard or APA Style
Dallimore, J. (2025 February 16). Caerphilly Castle. The Archaeology Addict. Retrieved from https://thearchaeologyaddict.wixsite.com/thearchaeologyaddict/post/caerphilly-castle
MLA Style
Dallimore, Jessica J. "Caerphilly Castle" The Archaeology Addict. The Archaeology Addict. 16 Feb 2025. https://thearchaeologyaddict.wixsite.com/thearchaeologyaddict/post/caerphilly-castle
Chicago Style
Dallimore, Jessica J. "Caerphilly Castle" The Archaeology Addict. Last modified February 16, 2025. https://thearchaeologyaddict.wixsite.com/thearchaeologya
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