At the beginning of the 5th century the Roman Empire started to collapse and the legions were called back from Britain. The vacuum of power was taken up by a king called Vortigern, but he was pressed on all sides by the Picts and the Scotti who saw the loss of the legions as an opportunity to advance over the borders that the Romans had steadfastly guarded.
In desperation Vortigern hired Saxon mercenaries to supplement his own armies, but before long the Saxons began to seize British land for their own and resisted all attempts to send them back to their own lands.
Vortigern called together his advisors and between them they devised a plan to retreat westward into the mountains of Snowdonia and there to build a mighty fortress at Dinas Emrys from which to consolidate his power.
From all over the realm, the King sent for masons and carpenters and collected the materials needed. Invocations to the gods were made by the Druids. With a silver knife they cut mistletoe and with music and song they dedicated the spot.
Vortigern set the craftsmen to work promising rich rewards to encourage the swift completion of the project.
Work was progressing well, but the workers awoke one morning to see all their toil had crumbled to the ground overnight. The King and his advisors were puzzled by this and the priest and bards had no answers either.
Once again the craftsmen set to work, even the women helped dragging logs and stones for the construction. Once again as the fortress began to take shape the walls collapsed overnight.
A third time the work proceeded with even more labour summoned to the construction, but once again the walls were solidly in place one night and then the following morning tumbled to the ground. Obviously some supernatural force was at work here.
With the Saxon hordes growing ever closer the Druids were summoned to placate the evil spirits that were assumed to be the cause of the demolition.
In desperation they looked to the old lore and said, “A child must be found who was born without a father. He must be brought here and his life-blood used to consecrate the foundations and placate the spirits.”
To this end a young boy called Myrddin was brought before the King and his assembled priests. Far from being cowed by his fate, the young boy stood firm and called for the Druids to explain why the walls fell each time.
The priests found themselves unable to give an explanation and the young Myrddin challenged “If you can not say with certainty how the walls fall, how can you be sure that a sacrifice will save them?”
When the priests could not answer he continued, “the ground here appears solid but below the surface lies a pool, have your men dig and the truth of this shall be shown.”
And when the men dug at the place indicated the pit rapidly filled with clear water.
“Inside the pool, ” Myrddin continued, “two mighty dragons come forth to battle, the first white as milk and the other red as blood shaking the ground with each vicious blow.”
The boy summoned a vision before the assembled crowd, the dragons clashed with fire and claw. The white rose up first forcing the red to the ground. Three times the white dragon gained supremacy over the red, but as the white dragon gloated at its victory the red gathered its strength and striking one mighty blow overcame the white and devoured it.
“The pool is an emblem of the world. The white dragon is that of the Saxons,” explained Myrddin, “and the red of the true sons of Britain. They will contend with each other until the tribes of this land are united. Build your fortress elsewhere for this one will not stand whilst the dragons still fight.”
And thus did the young Merlin forsee the coming of the king that would unite the British against the Saxon hordes.