The image was one of many aspects of imperial iconography taken up by Early Christians after the Edict of Milan in 313, when the depiction of Jesus as a human figure, especially as a large figure detached from narrative contexts, was still a matter of controversy within Christianity.
Some Early Christians had believed that the True Cross had miraculously ascended to Heaven, where it remained in readiness to become the glorified "sign of the Son of man" (see below) at the Last Judgement.