King Vortigern's fortress in Snowdon kept tumbling each night after expert masons had worked on it. His wizards advised him to find a youth that never had a father and sprinkle his blood on the foundations. After looking throughout Britain Vortigern's men found such a youth in Wales, Merlin. In Vortigern's court Merlin's mother testified that Merlin's father had been a spirit, an incubus. In the face of imminent death Merlin appeared unafraid. He told the king that an underground lake prevented the fortress from standing. When he had given directions for the draining of the lake Merlin prophesied that two dragons lay asleep on the bottom, a red one and a white one. The dragons were duly found, and they awoke and began fighting. The red dragon won. Vortigern asked what this meant, and Merlin told him he would soon be defeated and killed. Ambrosius landed the next day and proceeded to conquer Britain.
Merlin retired from public view until King Ambrosius wanted to build a great memorial. Ambrosius sent for the magician, who advised him to obtain the Dance of Giants stones from Ireland. Ambrosius' brother, Uther Pendragon, then defeated the Irish. With Merlin's help the huge stones were taken back to England and set up at Stonehenge. With the memorial completed, Merlin saw a blazing star in the shape of a dragon, an omen foretelling Ambrosius' death, the kingship of Uther Pendragon, and a future king — Uther's son — who would prove to be the greatest sovereign Britain would ever have.
