Although the emblem of Wales is a red dragon and dragons occasionally occur in Arthurian legend, there is no use of the dragon as an animal emblem in the early artwork of the Celts nor in the early illustrated manuscripts of the monasteries. In fact, although snakes or serpents (associated with Christ) find their home in the Book of Kells, the dragon seems to have been brought to the British isles by the Vikings. The intertwined dragons on this page are from a Late Medieval Irish source.
In the Mabinogion, a collection of medieval Welsh stories, in the tale of Lludd and Liewelys, there is a struggle between a white dragon and a red dragon. The red dragon represents Wales and the white dragon represents the invading Saxons. In the end, both dragons get drunk with mead and are buried in the center of the island of Britain, at Oxford, in a stone coffin. The white dragon comes to symbolize death, with its absence of color, and the red takes on the role of anger. Their internment together unites their fates but they could rise together, ready to repel invaders at any time. In Arthurian legend, Uther Pendragon, the father of King Arthur, was supposed to have used the dragon as his symbol in war. Even today, the red dragon is a part of the coat of arms of the Prince of Wales.
In later Christian iconography, the dragon appears most often as a symbol of the devil. The battles of St. George and St. Michael symbolize the perpetual struggle between good and evil.