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123 Welsh castle facts, all checked

Every fact on this site in one place, each linked to its source. Our build checks each one against the source text; see the sources page. Things that can change carry the date we checked them, and where sources disagree you’ll find both.

Jump to: Wales and the Welsh princes | Spotting and shapes | Edward I and the conquest | Castles and places (some dated) | The national curriculum | Where sources differ

Wales and the Welsh princes

  1. 1 With the remains of up to 500 earthwork and stone castles, Cadw calls Wales truly “a land of castles”. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  2. 2 The large number reflects how power and land were split up in medieval Wales, when castles asserted authority and defended land. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  3. 3 Most castles in Wales were built by the kings of England or the Anglo-Norman lords of the March, the borderland between England and Wales. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  4. 4 Welsh-held lands were divided between Gwynedd (north-west), Deheubarth (south-west), Powys (east) and several smaller realms. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  5. 5 But the Welsh were castle builders too, defending their land from each other and from invasion, and protecting important routes. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  6. 6 Rhys ap Gruffudd, the Lord Rhys, prince of Deheubarth (died 1197), was one of the greatest Welsh leaders of the 12th century. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  7. 7 In the 13th century the princes of Gwynedd were the first Welsh princes to claim rule over all of Wales. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  8. 8 They were led above all by Llywelyn ap Iorwerth (died 1240) and his grandson Llywelyn ap Gruffudd (died 1282). Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  9. 9 Llywelyn ap Iorwerth, Llywelyn the Great, was the undisputed ruler of Gwynedd from 1201 to his death in 1240. Cadw: Castell Dolwyddelan
  10. 10 Cadw calls Llywelyn ap Iorwerth the most active castle builder among the Welsh princes. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  11. 11 Fewer than 30 surviving castles in Wales are formally recorded as Welsh foundations, though the original number must have been much higher. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  12. 12 All the known castles of the Welsh lords and princes are now protected as scheduled monuments. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  13. 13 Early Welsh princes preferred moving between undefended courts (llysoedd) spread across their lands. Cadw: More about Castell Dolwyddelan
  14. 14 Not until the 13th century did Welsh princes build stone castles as mighty as those of the Marcher lords. Cadw: More about Castell Dolwyddelan
  15. 15 Castles put a big strain on a prince’s purse. Cadw: More about Castell Dolwyddelan
  16. 16 In 1267 Henry III formally recognised Llywelyn ap Gruffudd as prince of Wales in the Treaty of Montgomery. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  17. 17 A granite monolith at Cilmeri marks where Llywelyn ap Gruffudd, the last native prince of Wales, is believed to have been killed in 1282. Cadw: Castles of the Lords and Princes of Wales
  18. 18 His death marked the end of independent, native rule in Wales. Cadw: Castles of the Lords and Princes of Wales
  19. 19 Tradition says that on his last night, in December 1282, he hid in a cave near Aberedw and had his horse’s shoes put on backwards so he could not be tracked in the snow. Cadw: Castles of the Lords and Princes of Wales
  20. 20 Llys Rhosyr on Anglesey was one of Llywelyn ap Iorwerth’s royal courts; a sandstorm buried it in 1300, and it was rediscovered in 1992. Cadw: Castles of the Lords and Princes of Wales
  21. 21 Owain Glyndŵr raised his standard at Glyndyfrdwy in 1400, signalling his great uprising. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)

Spotting and shapes

  1. 22 Unlike the geometric English fortresses, Welsh castles tend to be irregular, made to fit their rocky settings. Cadw: More about Castell Dolwyddelan
  2. 23 Deep rock-cut ditches often strengthened their natural defences. Cadw: More about Castell Dolwyddelan
  3. 24 Welsh castles had lower walls, and characteristic D-shaped (not round) towers that were the real strongholds. Cadw: More about Castell Dolwyddelan
  4. 25 A Welsh D-shaped tower is rectangular with one half-rounded end: a roomy living chamber, with a wide field of fire from the rounded end. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  5. 26 Concentric castles have “walls within walls”: an inner ring of defences inside an outer one. Cadw: Castell Rhuddlan
  6. 27 UNESCO lists the features still on show: barbicans, drawbridges, fortified gates, chicanes, redoubts, dungeons, towers and curtain walls. UNESCO World Heritage Centre: Castles and Town Walls of King Edward in Gwynedd
  7. 28 Edward I liked his castles on the coast, so supplies could still arrive by sea if a campaign ran into trouble. Cadw: Castell Rhuddlan
  8. 29 Edward did not just build castles: he created English towns to go with them. Cadw: More about Beaumaris Castle
  9. 30 Traces of lime render show that Conwy Castle was originally white. Cadw: More about Castell Conwy

Edward I and the conquest

  1. 31 Edward I reigned from 1272 to 1307. UNESCO World Heritage Centre: Castles and Town Walls of King Edward in Gwynedd
  2. 32 Edward I led two campaigns in Wales, in 1276–77 and 1282–83, to defeat the Welsh princes and bring Wales under English rule. Cadw: The Castles and Town Walls of King Edward
  3. 33 Between 1276 and 1295 many castles were built or repaired. Cadw: The Castles and Town Walls of King Edward
  4. 34 Cadw calls Beaumaris, Caernarfon, Conwy and Harlech the finest castles Edward I built in Wales. Cadw: The Castles and Town Walls of King Edward
  5. 35 At Caernarfon and Conwy, new towns were built inside massive walls at the same time as the castles. Cadw: The Castles and Town Walls of King Edward
  6. 36 The four castles and two sets of town walls became a World Heritage Site in 1986. Cadw: The Castles and Town Walls of King Edward
  7. 37 UNESCO calls them the finest examples of late 13th- and early 14th-century military architecture in Europe. UNESCO World Heritage Centre: Castles and Town Walls of King Edward in Gwynedd
  8. 38 James of St George (about 1230–1309) was Edward I’s chief architect; UNESCO calls him the greatest military architect of the age. UNESCO World Heritage Centre: Castles and Town Walls of King Edward in Gwynedd
  9. 39 James of St George was also constable of Harlech from 1290 to 1293. UNESCO World Heritage Centre: Castles and Town Walls of King Edward in Gwynedd
  10. 40 The building of these royal castles is fully documented: the accounts name where the workmen came from, from all over England. UNESCO World Heritage Centre: Castles and Town Walls of King Edward in Gwynedd
  11. 41 Work was at times held up by the Welsh uprising of Madog ap Llewelyn in 1294. UNESCO World Heritage Centre: Castles and Town Walls of King Edward in Gwynedd
  12. 42 UNESCO says building went on until 1330 at Caernarfon and 1331 at Beaumaris. UNESCO World Heritage Centre: Castles and Town Walls of King Edward in Gwynedd
  13. 43 Cadw says all four were begun and substantially completed between 1283 and 1330. Cadw: The Castles and Town Walls of King Edward
  14. 44 After Llywelyn the Last’s death, Edward I laid down the law in Wales with the Statute of Rhuddlan, creating the shires of Flint, Caernarfon, Anglesey, Merioneth, Cardigan and Carmarthen. Cadw: More about Castell Rhuddlan
  15. 45 That system of government lasted until Henry VIII’s Act of Union in 1536. Cadw: More about Castell Rhuddlan
  16. 46 Edward of Caernarfon, born at Caernarfon on 25 April 1284, was the very first English Prince of Wales. Cadw: More about Castell Caernarfon
  17. 47 He was named Prince of Wales in 1301. Cadw: More about Castell Rhuddlan
  18. 48 Edward I was called Longshanks because of his great height. Cadw: More about Beaumaris Castle
  19. 49 Aberconwy Abbey, where Llywelyn the Great was buried, was forced to move 12km down the Conwy Valley to Maenan after Edward built Conwy castle and town. Cadw: Castles of the Lords and Princes of Wales

Castles and places (some dated)

  1. 50 Cadw says Caernarfon is recognised around the world as one of the greatest buildings of the Middle Ages. Cadw: Castell Caernarfon
  2. 51 Castle, town walls and quay were built at the same time; the project took 47 years and cost £25,000. Cadw: Castell Caernarfon
  3. 52 Its many-sided towers, eagle statues and multi-coloured stonework echoed imperial Roman architecture, especially the walls of Constantinople. Cadw: Castell Caernarfon
  4. 53 They also recalled the Welsh story of Macsen Wledig, who dreamed of a great fort at the mouth of a river. Cadw: Castell Caernarfon
  5. 54 The Eagle Tower has three great turrets and walls 18 feet thick. Cadw: More about Castell Caernarfon
  6. 55 Caernarfon hosted the investiture of Prince Edward in 1911 and of Prince Charles in 1969. Cadw: More about Castell Caernarfon
  7. 56 Conwy’s castle and town walls were built in about four years, between 1283 and 1287. Cadw: Castell Conwy
  8. 57 Conwy is still ringed by an unbroken 1.3km (1,400-yard) circuit of town walls. Cadw: Castell Conwy
  9. 58 Conwy has a high curtain wall and eight lofty towers. Cadw: Castell Conwy
  10. 59 It has the most intact set of medieval royal apartments in Wales. Cadw: Castell Conwy
  11. 60 At Conwy, master mason James of St George raised the towers and curtain wall first, then built the royal apartments inside. Cadw: More about Castell Conwy
  12. 61 Edward I spent £15,000 on Conwy but stayed only once: trapped by the rising of 1294, he spent Christmas there with one barrel of wine. Cadw: More about Castell Conwy
  13. 62 Harlech was finished from ground to battlements in just seven years. Cadw: Castell Harlech
  14. 63 When cut off by the rising of Madog ap Llewelyn, Harlech was supplied by ship up the “Way from the Sea”, a path of 108 steps. Cadw: Castell Harlech
  15. 64 Owain Glyndŵr took Harlech in 1404 and made it his main residence and court. Cadw: More about Castell Harlech
  16. 65 By 1409 Harlech was besieged by Harry of Monmouth, later Henry V. Cadw: More about Castell Harlech
  17. 66 Harlech was the last royalist stronghold to fall in the Civil War, surrendering in 1647. Cadw: More about Castell Harlech
  18. 67 Cadw says Harlech, with its many sieges, inspired the rousing song “Men of Harlech”, a tale of heroism against overwhelming odds. Cadw: More about Castell Harlech
  19. 68 Beaumaris was the last royal castle Edward I built in Wales. Cadw: Beaumaris Castle
  20. 69 Its name comes from “beau mareys”, beautiful marsh, beside the Menai Strait. Cadw: Beaumaris Castle
  21. 70 It has four rings of defences, a water-filled moat with its own dock, and 300 arrow loops in the outer walls. Cadw: Beaumaris Castle
  22. 71 Lack of money and trouble in Scotland meant work petered out by the 1320s, leaving it unfinished. Cadw: Beaumaris Castle
  23. 72 Edward’s troops began pulling down the Welsh town of Llanfaes in 1295, and many people were moved to Newborough. Cadw: More about Beaumaris Castle
  24. 73 By 1305 Beaumaris had 132 “burgages” or properties, the biggest borough in north Wales. Cadw: More about Beaumaris Castle
  25. 74 Rhuddlan, begun in 1277, was the first of James of St George’s concentric castles. Cadw: Castell Rhuddlan
  26. 75 Hundreds of ditch-diggers deepened and moved the River Clwyd so ships could reach Rhuddlan. Cadw: Castell Rhuddlan
  27. 76 Rhuddlan was completed in 1282 at a cost of £9,613. Cadw: More about Castell Rhuddlan
  28. 77 One of a group of fortresses built to command the mountain passes of Eryri (Snowdonia), Dolwyddelan is a lasting memorial to Llywelyn the Great. Cadw: Castell Dolwyddelan
  29. 78 Edward I took Dolwyddelan in 1283; the garrison was given white tunics for winter warfare in the mountains. Cadw: Castell Dolwyddelan
  30. 79 Llywelyn’s castle had a two-storey rectangular keep, with the main chamber above an unlit basement. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  31. 80 In the 19th century Lord Willoughby de Eresby added medieval-style battlements to the keep. Cadw: Castell Dolwyddelan
  32. 81 Tradition says Dolwyddelan was Llywelyn ap Iorwerth’s birthplace. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  33. 82 Criccieth’s great gatehouse, with D-shaped towers, was built by Llywelyn the Great; his grandson added the outer ward. Cadw: Castell Cricieth
  34. 83 After Edward I took it, the north tower was fitted with a stone-throwing machine. Cadw: Castell Cricieth
  35. 84 In the 14th century the bard Iolo Goch praised Criccieth as ‘the bright fort high on a rock’ and the court of Sir Hywel of the Axe. Cadw: More about Castell Cricieth
  36. 85 Sir Hywel was constable of Criccieth for more than 20 years, until his death in 1381. Cadw: More about Castell Cricieth
  37. 86 In 1404 Owain Glyndŵr’s forces burnt the towers red. Cadw: Castell Cricieth
  38. 87 Around 1359 Sir Hywel y Fwyall (Hywel of the Axe) became Criccieth’s first Welsh constable. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  39. 88 J. M. W. Turner painted Criccieth when it was already a ruin. Cadw: Castell Cricieth
  40. 89 Castell y Bere was begun by Llywelyn the Great in 1221 and stayed in use until 1294. Cadw: Castell y Bere
  41. 90 Its entrance, with two gate-towers each with a drawbridge, was very advanced for its time, even by English standards. Cadw: More about Castell y Bere
  42. 91 It guarded Llywelyn’s cattle range: in medieval Wales cattle were as good as money. Cadw: More about Castell y Bere
  43. 92 Llywelyn took the site from his own son Gruffudd in 1221 to build the castle. Cadw: More about Castell y Bere
  44. 93 Dolbadarn’s round tower stands 15.2m (50ft) high above Llyn Padarn. Cadw: Castell Dolbadarn
  45. 94 Cadw calls Dolbadarn the finest surviving example of a Welsh round tower. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  46. 95 Llywelyn ap Gruffudd is said to have kept his brother Owain prisoner there for two decades. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  47. 96 Its curtain walls are made of unmortared slate slabs. Cadw: Castell Dolbadarn
  48. 97 At Ewloe, the evidence now seems to favour Llywelyn ap Iorwerth as the first builder. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  49. 98 Castell Dinas Brân above Llangollen was built by Madog ap Llywelyn of Powys Fadog, probably in the 1260s. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  50. 99 Caergwrle, built 1278–83 by Dafydd ap Gruffudd, was the last castle built by a native Welsh prince. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  51. 100 Llywelyn ap Gruffudd began Dolforwyn in 1273, to rival the royal castle at Montgomery 4 miles away. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  52. 101 Dryslwyn became one of the largest stone castles ever raised by the native Welsh lords. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  53. 102 Gilbert de Clare began Caerphilly in 1268, fearing Llywelyn ap Gruffudd; it is the biggest castle in Wales. Cadw: Caerphilly Castle
  54. 103 With its water defences it covers 30 acres, second only to Windsor in Britain. Cadw: Caerphilly Castle
  55. 104 Llywelyn ap Gruffudd twice tried to knock it down before it was finished. Cadw: Caerphilly Castle
  56. 105 Its leaning south-east tower leans more than the Leaning Tower of Pisa. Cadw: Caerphilly Castle
  57. 106 The fourth Marquess of Bute restored the castle from 1928; half of what you see today is down to him. Cadw: More about Caerphilly Castle
  58. 107 Cadw lists Castell y Bere as free entry, open all year in reasonable daylight hours. Cadw: Castell y Bere · checked 31 Oct 2026
  59. 108 Cadw lists Dolbadarn as free entry and open all year. Cadw: Castell Dolbadarn · checked 31 Oct 2026
  60. 109 Dolwyddelan’s interior opens April to September on Fridays, Saturdays, Sundays and bank holidays; on other days it is external viewing only. Cadw: Castell Dolwyddelan · checked 31 Oct 2026

The national curriculum

  1. 110 In England’s national curriculum, a KS2 local history study can be of a site from a period beyond 1066 that is significant in the area. GOV.UK (DfE): National curriculum in England, history programmes of study
  2. 111 KS2 pupils also study an aspect or theme in British history that extends their knowledge beyond 1066. GOV.UK (DfE): National curriculum in England, history programmes of study
  3. 112 At KS3, pupils study Church, state and society in Medieval Britain 1066–1509. GOV.UK (DfE): National curriculum in England, history programmes of study
  4. 113 KS3 examples include English campaigns to conquer Wales and Scotland up to 1314. GOV.UK (DfE): National curriculum in England, history programmes of study

Where sources differ

  1. 114 Cadw’s Dolwyddelan page says that out of more than 470 fortresses in Wales, fewer than 40 were definitely built by native hands. Cadw: More about Castell Dolwyddelan
  2. 115 Cadw’s Dolbadarn page says it was most likely built by Llywelyn the Great in the late 12th or early 13th century. Cadw: Castell Dolbadarn
  3. 116 Cadw’s booklet says it was probably built in the last decades before his death in 1240. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  4. 117 Cadw says Llywelyn began Dolwyddelan some time after 1210. Cadw: More about Castell Dolwyddelan
  5. 118 Cadw’s booklet says probably between 1210 and his death in 1240, replacing an earlier castle, Tomen Castell. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  6. 119 Cadw’s booklet says Criccieth was begun by Llywelyn ap Iorwerth in the 1230s. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  7. 120 Cadw’s booklet notes that some parts of Castell y Bere may have been built by his grandson, Llywelyn ap Gruffudd. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  8. 121 The booklet says the English seem to have abandoned Castell y Bere by the end of the 13th century; Cadw’s history page says they left during an uprising in 1294. Cadw: More about Castell y Bere
  9. 122 The booklet says Glyndŵr’s forces besieged Criccieth in 1403 and it was later destroyed. Cadw booklet: The Castles of the Lords and Princes of Wales (PDF)
  10. 123 Cadw’s Beaumaris page says building had petered out by the 1320s. Cadw: Beaumaris Castle