Welsh flag

[Riverghost]

Can anyone tell me why the Welsh flag is the red dragon and not St. David's Cross?

[Philtaz]

Y Ddraig Goch(the Red Dragon) was used as a crest by the early Welsh kings, Arthur, Cadwallon and Cadwaladr and at the Battle Of Bosworth Henry Tudor unfurled his standard bearing a red dragon on a green and white background.

As it was first used by the kings this is the more likely reason for it being the Red Dragon as opposed to the Cross of St David.

[Romeo]

There are different versions of how the Red Dragon came to be the symbol of Wales.  In one, Merlin (Myrddin) is asked by a Welsh prince to excorcise two dragons that live under his castle.  When Merlin casts the dragons out, they fight in the air.  The red one wins and flies off victoriously, and becomes a symbol of victory.  In a further development of the legend, the white dragon represents England or the Saxons and the red dragon represents Wales or the Celts. 

[Octavius]

The origins of the Red Dragon flag, or "y Draig Goch" could date back to the Roman period, when the dragon (or draco) was used by Roman military cohorts at the time of the Emperor Trajan. After the Romans left, the Red Dragon remained as a key emblem of Wales and there are accounts of battles against the Saxons under the Red Dragon. The Tudors adopted the Red Dragon, and the Welsh-born future Henry VII took to the battle of Bosworth Field under the Red Dragon standard.