When Constantine the Great carried the seat of empire from Rome to Constantinople he set up in the marketplace of the new capital a porphyry pillar which had come from Egypt, and of which a strange tale is told. In a vault beneath he secretly buried the seven sacred emblems of the Roman State, which were guarded by the virgins in the temple of Vesta, with the fire that might never be quenched. On the summit he raised a statue of Apollo, representing himself, and enclosing a fragment of the Cross; and he crowned it with a diadem of rays consisting of the nails employed at the Crucifixion, which his mother was believed to have found at Jerusalem. The pillar still stands, the most significant monument that exists of the converted empire; for the notion that the nails which had pierced the body of Christ became a fit ornament for a heathen idol as soon as it was called by the name of a living emperor indicates the position designed for Christianity in the imperial structure of Constantine. Diocletian's attempt to transform the Roman Government into a despotism of the Eastern type had brought on the last and most serious persecution of the Christians; and Constantine, in adopting their faith, intended neither to abandon his predecessor's scheme of policy nor to renounce the fascinations of arbitrary authority, but to strengthen his throne with the support of a religion which had astonished the world by its power of resistance, and to obtain that support absolutely and without a drawback he fixed the seat of his government in the East, with a patriarch of his own creation. Nobody warned him that by promoting the Christian religion he was tying one of his hands, and surrendering the prerogative of the Caesars. As the acknowledged author of the liberty and superiority of the Church, he was appealed to as the guardian of her unity. He admitted the obligation; he accepted the trust; and the divisions that prevailed among the Christians supplied his successors with many opportunities of extending that protectorate, and preventing any reduction of the claims or of the resources of imperialism.