Power on earth was once - and sometimes even now - perceived as a result of power in heaven. The great double mosaic of Justinian and Theodora at San Vitale in Ravenna is a forceful exercise in demonstrating power through art as propaganda, fusing political and religious imagery for a double statement of authority. In the 6th century, many intellectual Christians, not necessarily an oxymoron despite the possibility thereof, would have found these mosaics hubristic. Even the cynical could have found these mosaics troubling. Yet there are at least three possible reasons why this propaganda was justifiable for a Byzantine ruler. The mosaics here are perhaps the greatest of early Byzantine if not all post-Roman mosaics; they do serve as