Title: The Book of Taliesin. He is a shapeshifter; a seer; a chronicler of battles fought, by sword and with magic, between the ancient kingdoms of the British Isles; a bridge between old Welsh mythologies and the new Christian theology; a 6th-century Brythonic bard; and a legendary collective project spanning the centuries up toThe Book of Taliesin 's compilation in 14th-century North Wales.