The plot of the apocryphal Legend of Abgar revolves around the story of the first royal conversion to Christianity. The Legend, the importance of which was underlined first by citing a letter supposedly written by Jesus to king Abgar (which soon became regarded as a protective amulet), and later by the inclusion of an account of an image of Christ not made by human hands, became so popular in the Christian world that it not only constituted a part of its historical writings and ecclesiastical collections but is still alive today thanks to debates about the erroneous connection with the Turin Shroud.