Wales History Map: Princes of Gwynedd

The princes of Gwynedd reigned for more than 800 years — centuries that saw bloody internal battles and clashes with the English crown, but also cultural growth, religious and social change and the construction of many awe-inspiring buildings.

Their dynasty left a permanent mark on the landscape of Wales and helped to forge the proud national identity which still stands strong today.

The compelling tale of Gwynedd’s princely rulers includes some of the most significant figures in Welsh history — from Rhodri Mawr, who defeated Viking invaders in 856, to Llywelyn ap Gruffudd, who was recognised by Henry III of England as  Prince of Wales in 1267 (only to be killed by Edward I’s forces in 1282).

Today, you can experience the legacy of the princes’ reign in the stunning landscape of north Wales.

Deganwy Castle

Castell Deganwy | Deganwy Castle

What? Ruins of a castle first mentioned in records dating back to the 8th century
Where? Deganwy, Conwy

Deganwy Castle altered form and changed hands on many occasions over the centuries, with a number of documented Welsh and Norman owners. Most of what you see at the site today was built by Henry III. The castle was eventually captured and systematically dismantled by Llywelyn ap Gruffudd — a significant moment in Llywelyn’s campaign against Henry.

Due to the castle’s turbulent past, not a great deal has survived to the present day. However traces do remain, and the site itself, atop a steep hill, offers commanding views of the mouth of the river Conwy and Edward I’s spectacular Conwy Castle.

Why not start your tour of the princes' domain by surveying Maelgwn's lands as he would have done nearly fifteen centuries ago?

Did you know..? The castle lies at an elevation of 110m above sea level, sprawled over
two volcanic plugs.

Deganwy Castle
LL31 9PJ

Admission free.

Llys Rhosyr 

Llys Rhosyr | Llys Rhosyr

What? The remains of a medieval Welsh court
Where? Newborough, Anglesey

Lying undiscovered until 1992, the excavation of the site has revealed the only medieval Welsh court you can actually visit. 

Welsh royalty divided their territories in to administrative areas, each of which had its own ‘Llys’ or court. The princes would travel to these courts on official business, including tax collection and overseeing legal matters. 

Here at Llys Rhosyr, the excavations revealed many artefacts from the 13th century as well as the stone remains of three structures, including a hall and an area with ovens. 

Did you know..? Three quarters of the site remains unexplored by archaeologists, but what you can see provides a fascinating insight into medieval Welsh society.

Admission free.

To add to your enjoyment of the site a downloadable audio tour is available from

Dolbadarn Castle

Castell Dolbadarn | Dolbadarn Castle

What? Ruined 13th century castle
Where? Llanberis

Built by Llywelyn ap Iorwerth (Llywelyn ap Grufudd’s powerful grandfather), Dolbadarn Castle was a potent symbol of his status and wealth.

The castle was intended to guard the entrance of the Llanberis Pass, and later became a royal prison.

Llywelyn ap Gruffudd had fought tirelessly against his brothers to become the overall overarching Prince of Gwynedd. But even in defeat, the brothers posed a serious threat.

Llywelyn’s solution? To imprison them, keeping his elder brother, Owain Goch, within the castle’s prison for twenty-two years – a 50ft round tower which still dominates the site to this day.

Did you know..? Historians believe Owain Goch was held here because the 13th century poet Hywel Foel ap Griffi described Owain as ‘a man in a tower, long a guest’.

Dolbadarn Castle
Llanberis LL55 4TA

Admission free.

Criccieth Castle

Castell Cricieth | Criccieth Castle

What? A 13th century castle built upon rocky headland
Where? Criccieth, Gwynedd

Built sometime during the 13th century, Criccieth Castle is perched upon a steep headland overlooking Tremadog Bay. Don’t be fooled by the site’s beautiful views across the water - Criccieth’s twin-towered gatehouse is an intimidating structure. 

Originally built by Llywelyn ap Iorwerth, this Welsh prince included a very English style gatehouse. Edward I’s forces took the castle some 50 years later, and made a number of changes to its fabric.

Did you know..? During the 13th century, Criccieth Castle housed many political prisoners including Gruffudd ap Llywelyn and Maredudd ap Rhys Gryg.

The castle’s visitor centre helps tell the story of the Princes of Gwynedd.
Criccieth Castle
Castle Street,
LL55 0DP

Admission charged.