“Examine it carefully and you will penetrate to the very shrine of art. You will make out intricacies so delicate and subtle, so concise and compact, so full of knots and lines, with colours so fresh and vivid, that you might think all this was the work of an angel, not a man.”

—Giraldus de Barri, twelfth century, on one of the great Celtic manuscripts, perhaps the Book of Kells.