In the Middle Ages, the legend assumed another form. Duke Richard, surnamed 'Richard sans peur', walking with his courtiers one evening in the forest of Moulineaux, near one of his castles on the banks of Seine, hearing of a prodigious noise coming towards him, sent one of his esquires to know what was the matter, who brought him word that it was a company of people under a leader or King. Richard, with five hundred of his bravest Normans, went out to see a sight which the peasants were so accustomed to that they viewed it two or three times a week without fee. The sight was of the troop, preceded by two men, who spread a cloth on the ground, made all the Normans run away, and leave the Duke alone. He saw the strangers form themselves into a circle on the cloth, and on asking who they were, was told that they were the spirits of Charles V, King of France, and his servants, condemned to expiate their sins by fighting all night against the wicked and the damned. Richard desired to be of their party, and receiving a strict charge not to quit the cloth, was conveyed with them to Mount SInai, where, leaving them without quitting the cloth, he said his prayers in the Church of St. Catherine's Abbey there, while they were fighting, and returned with them. In proof of the truth of this story, he brought back half the wedding-ring of a knight in that convent, whose wife, after six years, concluded him dead, and was going to take a second husband.
Note in the Lucknow Edition of The Nights, p. 425
Burton, Richard F., Supplemental Nights to the Book of the Thousand Nights and Night
Volume XIV, Eaton Press, Norwalk, Connecticut.