Morlais Castle

Has been described as a Certain Masonry Castle

There are masonry footings remains

NameMorlais Castle
Alternative NamesCastell Morlais
Historic CountryGlamorgan
Modern AuthorityMerthyr Tydfil
1974 AuthorityMid Glamorgan

Morlais Castle was a colossal site but is now buried under its own wreckage and only fragments of masonry can be discerned amid its tumultuous screes. The castle was built amid much controversy by the lord of Glamorgan from about 1288, marking the northern bounds of the newy annexed upland commotes of Senghenydd. It was captured by rebels in 1294 and may never have been restored. The castle stands on the summit of a high limestone ridge in what was one of the most fertile and productive parts of the Glamorgan uplands. It consists of a great walled enclosure studded with towers, roughly 130m north-south by 60m. The western walls are set above steep slopes and the towers face south and east. At the southern and northern ends were vast round towers, about 20m in diameter, great symbols of lordship that would have dominated the castle's skyline. The fine vaulted basement of the great south tower survives intact. Within the walls are traces of halls and apartments and their associated offices, as well as a great rock-cut cistern. This great court is surrounded by a massive rock-cut ditch some 15m wide with a counterscarp bank beyond. An outer court on the south side is enclosed only by earthworks. These are cut by the rock-cut ditch and this has prompted the suggestion that the outer court represents the remains of an earlier fortress. However, it is possible that this section of the great ditch has been enlarged and extended through limestone quarrying associated with the adjacent limekiln depicted on the 1st edition OS County series (Glamorgan. VI.9 1875). Traces of a relict field system have been recorded from the air north-east of the castle. This could belong to a later period if it is not associated with the castle


This strong castle on the northern border of Senghennydd Uwch Caeach near Merthyr Tydfil is largely reduced to rubble, but despite its condition and brief history it is of considerable archaeological, architectural and historical interest. Founded by Gilbert II de Clare c1288, it thereafter marked the northern limit of Glamorgan and symbolised the final subjugation of the upland commotes. It consists of a long oval-shaped hill-top site with a bank & ditch all round. Inside the ditch is the curtain wall, now mostly collapsed but still standing in places. It may have been abandoned as early as 1295, following on-going Welsh rebellion against the English. (Glamorgan-Gwent Archaeological Trust HER)

Within an Iron Age hillfort on a limestone ridge are the last traces of the large and strong castle begun in c1287 by Gilbert de Clare, on land claimed by Humphrey de Bohun. Warfare broke out between the earls in 1290 and they were severely admonished and fined by Edward I. The castle was captured by Madog ap Llywelyn in 1294. It was probably never fully completed and was too remote and exposed to serve as a residence. The castle comprising a triangular inner ward with sides about 45m long and an inner bailey 60m wide. The inner ward had a round keep 17m in diameter at the north corner, a D-shaped tower with a staircase on the north side at the SE corner, and a similar tower projected from the south wall. (Salter, 1991)

This site is a scheduled monument protected by law

Not Listed

The National Monument Record (Coflein) number(s)
County Historic Environment Record
OS Map Grid ReferenceSO049095
HyperLink HyperLink HyperLink

No photos available. If you can provide pictures please contact Castlefacts

Most of the sites or buildings recorded in this web site are NOT open to the public and permission to visit a site must always be sought from the landowner or tenant.

Calculate Print


  • Davis, Paul, R., 2011, The Forgotten Castles of Wales (Almeley: Logaston Press) p. 125-31
  • Goodall, John, 2011, The English Castle 1066-1650 (Yale University Press) p. 203-4
  • Kenyon, John, 2010, The Medieval Castles of Wales (University of Wales Press) p. 126-127
  • Morgan, Gerald, 2008, Castles in Wales: A Handbook (Talybont: Y Lolfa Cyf.) p. 149-51
  • < >RCAHMW, 2000, An Inventory of Ancient Monuments in Glamorgan Vol. 3 Part 1b: The Later Castles (London: HMSO) < > p. 208-229
  • Pettifer, Adrian, 2000, Welsh Castles, A Guide by Counties (Boydell Press) p. 99-100
  • Reid, Alan, 1998, Castles of Wales (John Jones Publishing) p. 108-9
  • Salter, Mike, 1991, The Castles of Gwent, Glamorgan and Gower (Malvern) p. 56
  • King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol. 1 p. 166
  • Davis, Paul R., 1983, Castles of Glamorgan (Alun Books) p. 18-9
  • Fry, P.S., 1980, Castles of the British Isles (David and Charles) p. 367
  • Hague, D.B., 1971, in Pugh, T.B. (ed), Glamorgan County History Vol. 3 The Middle Ages (Cardiff) p. 431-2
  • Oman, Charles W.C., 1926, Castles (1978 edn Beetham House: New York) p. 173
  • Clark, G.T., 1884, Mediaeval Military Architecture in England  (Wyman and Sons) Vol. 2 p. 312-22 (reprint of 1859 article) online copy
  • Lewis, Samual, 1849, A Topographical Dictionary of Wales online copy
  • Buck, Samuel and Nathenial, 1774, Buck’s Antiquities (London) Vol. 2 p. 403


  • Toulmin-Smith, Lucy (ed), 1906, Leland's Itinerary in Wales  (Bell and Sons; London) p. 18 online copy


  • Spurgeon, Jack, 1987, 'The Castles of Glamorgan' Château Gaillard Vol. 13 p. 215
  • Kenyon, John R., 1985, ‘Morlais Castle’ as viewed by Samuel and Nathaniel Buck’, Archaeologia Cambrensis Vol. 134 p. 235–7
  • Robinson DM., 1983, 'An Aerial survey at Morlais Castle, Mertyr Tydfil, Mid Glamorgan' Bulletin of the Board of Celtic Studies Vol. 30 p. 431-40
  • Hogg, A.H.A. and King, D.J.C., 1967, 'Masonry castles in Wales and the Marches: a list' Archaeologia Cambrensis Vol. 116 p. 71-132
  • Gardner, I., 1916, 'Morlais Castle, Glamorganshire' Archaeologia Cambrensis Vol. 71 p. 341-53 (weak history)
  • 1901, Archaeologia Cambrensis Vol. 56 p. 56-7 online copy
  • Clark, G.T., 1859, 'Some Account of Morlais Castle' Archaeologia Cambrensis Vol. 14 p. 97-114 online copy

Primary Sources

  • Lyte, H.C. Maxwell (ed), 1912, Calendar of various Chancery Rolls - Welsh Rolls 1277-1294 p. 337 online copy