The heraldic red dragon passant (walking with one leg raised) tattoo is virtually synonymous with Wales and being Welsh, appearing as the main design element in the flag of Wales known as the Y Ddraig Goch or the Red Dragon. Although this creature might seem like a descendent of dark Celtic myths and animals who jealously guarded their hordes in deep caves, the red dragon of Wales could very well be of Roman birth instead.
There is no direct evidence that Romans introduced the symbol of the dragon to the British Isles, but the scenario seems a likely one. During the 400 year Roman invasion and occupation of these distant islands, there would have been ample opportunity for Britains to have observed the draco (Latin for dragon), the battle standard carried by Roman troops. A red or purple dragon was used in the 4th century as the standard of the cohort (480 men) while the eagle was used for the legion (ten cohorts). The Romans, in turn, likely adopted this symbol of war and authority from their Sarmatian foes of the eastern steppes, taking draco standards as spoils of war, as documented by the reliefs on the base of emperor Trajan’s column. The draco was made of a metal dragon’s head and a tubular fabric body, not unlike a modern wind sock, with the fabric body flowing in the breeze behind the head.
The first British visual reference to a draco appears in the Bayeux tapestry, created ca. 1077 for Bishop Odo, the Earl of Kent, and the half-brother of William the Conqueror. The tapestry shows that both Normans and Saxons were using the draco during the Battle of Hastings (in which William the Conqueror, leader of the Normans, defeats Harold, King of the Saxons, in 1066). The dragon image was eventually adopted as a royal English ensign in the centuries that followed, and also used as an actual flag, but by the mid-fourteenth century, the dragon symbol was becoming less popular and had largely disappeared from royal use.
It would seem that the Welsh didn’t use any type of battle ensign until the late twelfth century–mentioned first in the History of Gruffyd ap Cynan, who died in 1137. From this same time period, we know that the words dragon, dragwn, draig in Welsh meant leader or chieftain. The earliest historical reference to the dragon used as a military ensign among the Welsh seems to be at the siege of Carnarvon, November 2, 1401, by Owen Glendower (in multitudine glomerosa vixillum suum album cum dracone aureo ibidem displicuit).
Finally, in terms of the historical symbolism, our earliest interpretation of a Welsh dragon comes from the Historia Britonum, purportedly written by Nennius, a Welsh monk of the 9th century:
At length the red one, apparently the weaker of the two, recovering his strength, expelled the white one from the tent; and the latter being pursued through the pool by the red one, disappeared. Then the boy, asking the wise men what was signified by this wonderful omen, and they expressing their ignorance, he said to the king, “I will now unfold to you the meaning of this mystery. The pool is the emblem of this world, and the tent that of your kingdom: the two serpents are two dragons; the red serpent is your dragon, but the white serpent is the dragon of the people who occupy several provinces and districts of Britain, even almost from sea to sea: at length, however, our people shall rise and drive away the Saxon race from beyond the sea, whence they originally came; but do you depart from this place, where you are not permitted to erect a citadel; I, to whom fate has allotted this mansion, shall remain here; whilst to you it is incumbent to seek other provinces, where you may build a fortress.”
Why use red for the dragon? Very early dragon ensigns were described variously as gold, red, and purple in color, although the description of colors is often faulty in early reports and the gold may have come from the metallic head of the early dracos. However, as far back as the paleolithic, which is essentially as far back as our record of the human use of coloring agents goes, red has been a significant, if not the most significant, color. Although we could look to an infinite number of cultures and peoples who have used red to symbolize everything from the hostile Egyptian god Seth to the flags of communist China, the overwhelming symbolism of red is blood and, hence, life, and by extension power.