The vast wooden disk known as King Arthur's Round Table has hung on the wall of the great Hall of Winchester Castle for six hundred years. But what is it? Was it ever a table? When was it made? Why is it hanging on the wall? When was it painted with the famous image it now bears? And why at Winchester? In 1976 the Round Table was taken down from the wall and thoroughly examined by a team of historians and scientists assembled by Martin Biddle, and its history began to emerge. Built in the reign of Edward I, it was probably the centrepiece of a feast held at Winchester after a forgotten tournament celebrating marriage plans for the king's children; Edward III, founder of the Order of the Garter, had the top hung up in the castle hall as a symbol of his interest in the chivalric idea of the company of Arthur's Round Table; Henry VIII had it painted and used the figure of Arthur to support his claim to be arbiter of European power. This most enigmatic of objects at last yields up these and other secrets to scientific analysis and historical deduction.