Castles are the most obvious reminder of mediaeval Wales. Symbolising the ambitions of the Welsh princes, the expansionist character of the Marcher lords and finally the subjection of an independent Wales by Edward I, castles were always more than just buildings.
The Normans introduced castles to Wales. The first castles were simple motte and bailey constructions, but they showed the locals who was in charge. In any uprising these symbols of oppression were the first target.
The Welsh princes soon realised the castle's usefulness as an offensive weapon and symbol of lordship. Early in the 12th century Cadwgan ap Bleddyn, prince of Powys, built a castle at Welshpool in reply to Roger Montgomery's nearby castle at Hen Domen. Princes like Owain ap Gruffudd of Gwynedd and Rhys ap Gruffudd of Deheubarth used castles to secure their frontiers. Soon there were hundreds of castles spread along the borderlands of Wales. Castles also provided secure accommodation for the prince and his family as at Cardigan for the princes of Deheubarth and at Dinas Brân for the princes of Powys Fadog.
Llywelyn the Great, prince of Gwynedd (1194-1240) used castles to ensure stability, both political and economic, in North Wales. His string of castles between Tegeingl (Flintshire) and Meirionydd protected the heartlands of his principality, controlled lines of communication, trade and possible invasion routes and shadowed the royal and marcher castles to the south. Castell y Bere, Degannwy, Dolwyddelan and Dolbadarn helped Llywelyn secure the economic and military resources he needed. The castles also reveal his organisational ability and an ambition to be more than simply prince of Gwynedd.
Similarly, his grandson Llywelyn ap Gruffudd (Llywelyn the Last) , on regaining Tegeingl in 1257, rebuilt the castle at Ewloe. Once secure in North Wales, Llywelyn sought to extend his power into mid Wales by building a castle at Dolforwyn in the Severn Valley. It was one castle too many for the Edward I, King of England. This new castle and a refusal to do homage were signs to Edward I that Llywelyn was a vassal who no longer knew his place. In 1277 Edward reminded him.