The Welsh Dragon
In the ancient Welsh myths of the 'Mabinogion', the story of Lludd and Llefelys tells of a red dragon fighting with an invading white dragon. It ends with Lludd, King of Britain, capturing both dragons and imprisoning them at Dinas Emrys in Gwynedd.
According to the ninth century 'Historia Brittonum', centuries pass and the dragons remain imprisoned at Dinas Emrys until King Vortigern tries to build a castle there. But every night the castle walls and foundations are demolished by unseen forces.
In Geoffrey of Monmouth's twelfth century account, Vortigern then meets the young Merlin who explains that an underground fight between the red and white dragons is causing his castle to collapse. Vortigern excavates the hill, freeing the dragons. They continue their fight and the red dragon finally defeats the white dragon.
The long fight of the dragons is symbolic of the historical struggle between the Welsh (red dragon) and the English (white dragon).