Taliesin by Stephen Lawhead
A magnificent tale which begins with the tragedy of Atlantis and the arrival in Britain of King Avallach. In this world, Celtic chieftains struggle for survival in the twilight of Rome's power, and one heroic figure towers over all, the Prince Taliesin, in whom is the sum of human greatness. This is a tale of a love that spawns the miracle of Merlin and Arthur and a destiny that is more than a kingdom.