Many visitors to the enormous Edward I built castle, Conwy Castle, are perhaps not aware that, just a short distance away across the estuary, lie the remnants of arguably the Kingdom of Gwynedd’s (and Cymru’s) most important llys (court): Castell Degannwy (spelled as “Deganwy” in English).
What Is Castell Degannwy?
The ruins of Castell Degannwy remain high above the Conwy Estuary. Inarguably, Degannwy was an important Welsh stronghold (so much so that many of its stones are believed to have gone into the building of Conwy Castle) coveted by many a foe.
Degannwy has its roots all the way back in the 6th century AD, when it was founded by Maelgwn Gwynedd; a powerful ruler of Gwynedd who was viewed as something of a “High King” among the other Brythonic kingdoms of the time, such as the former kingdom of Yr Hen Ogledd (the “Old North”) which covered what is today Cumbria and southern Alba.
Degannwy served as a significant royal residence and fortress, maintaining control over the fertile lands and strategic waterways that intersected at the Conwy Estuary. It would have been the headquarters for many a King of Gwynedd over the centuries.
In the years that followed, Castell Degannwy evolved into a formidable stone fortress (it was very likely fortified in stone by Llywelyn Fawr himself) and served as a symbol of Welsh power and resistance.
Degannwy was destroyed by Llywelyn ap Gruffudd (“The Last”) to prevent it falling, once more, into enemy hands.
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Niklas is the founder, owner, manager, editor, writer, video creator, voice over artist, and so forth, of Welsh Histories. He is passionate about the preservation of Welsh culture; the rejuvenation of the Welsh language and the promotion of Welsh history. Niklas currently resides in Pune, Maharashtra, with his beloved wife.

