Wales · Ruin
Cefnllys Castle
Cefnllys Castle was a medieval spur castle complex on Castle Bank above the River Ithon in what is now Powys, Wales. Two successive 13th-century masonry castles — a northern keep within a triangular inner bailey and a later southern castle with a circular/octagonal tower and walled court — dominated the ridge; both are now ruinous and only earthworks and rubble survive, while St Michael's Church at the foot of the hill remains standing.
Its prime
1275
Today
Ruin
As it stood in 1275
The shape it held in its prime.
Perched along the elongated ridge of Castle Bank above a looping bend of the River Ithon, the site comprised two masonry strongholds at opposite ends of the hill. The earlier northern castle had a keep set within an elevated triangular inner bailey and an outer bailey to its north-east; the later southern castle featured a circular (or octagonal) tower inside a walled court separated by a deep rock-cut ditch. A continuous stone curtain wall and rampart ran along much of the hilltop rim.
Its story
The story of Cefnllys Castle.
Cefnllys began as a motte-and-bailey thrown up during the early stages of the Norman invasion of Wales by the Anglo-Norman baron Ralph Mortimer — credited with building a castle in Maelienydd named 'Dynyetha', probably between 1093 and 1095 — beginning a long association between the powerful Mortimer family and the site. Around 1242 Ralph Mortimer II built a masonry castle on Castle Bank, the ridge above the River Ithon, and it quickly became the principal symbol of Mortimer hegemony in Wales.
In late November 1262 a small band of Welshmen entered the castle 'by treachery', capturing the constable Hywel ap Meurig and his family and torching it before sending word to Llywelyn ap Gruffudd. When Roger Mortimer arrived with an army of Marcher lords to repair the walls, Llywelyn surrounded him with a larger force. Cefnllys featured prominently in the Treaty of Montgomery, and Roger's construction of a second castle on the hill helped provoke Llywelyn's refusal to swear fealty to Edward I in 1275 — and war in 1277.
The castle may have been sacked in the revolts of Madog ap Llywelyn and Owain Glyndŵr, but remained occupied until at least the mid-15th century, when the bard Lewys Glyn Cothi described it in a series of poems. Both castles on Castle Bank are now entirely ruinous; the sole surviving medieval structure is St Michael's Church at the foot of the hill, and the medieval town beside it disappeared after the Black Death, though Cefnllys kept its borough status into the 19th century.
Step inside
9 places to explore in 1275.
The record describes 9 distinct spots at Cefnllys Castle — including 4 interiors: northern inner bailey and keep, southern walled court with circular/octagonal tower, large north bailey and oak hall site and more. Create your own photoreal reconstruction and walk through every one — more scenes means more photos, more angles and more rooms of the immersive experience.
Create History
Recreate Cefnllys Castle with AI to explore it.
The artist rebuilds it as it stood in 1275 — a photoreal walk that belongs to you alone. Pay with coins, no subscription needed.
Recreate Castle to Explore →Whose castle
Clans who held Cefnllys Castle.
The families that held Cefnllys Castle for a decade or more across its history — follow a name to its clan.
Mortimer
Seat of the Mortimers' lordship of Maelienydd from Ralph Mortimer's Norman motte of the 1090s through the masonry castles of the 13th century.
