No one is known to have seen his face because it was hidden by a mask of black velvet cloth, and the true identity of the prisoner remains a mystery; it has been extensively debated by historians, and various theories have been expounded in numerous books and films. | No one is known to have seen his face because it was hidden by a mask of black velvet cloth, and the true identity of the prisoner remains a mystery; it has been extensively debated by historians, and various theories have been expounded in numerous books and films. |