Cyril regarded the occasion as favourable for announcing to the Emperor Constantius the commencement of his Episcopate; and in his extant letter described the sign as a proof of God’s favour towards the Empire and its Christian ruler.  The piety of his father Constantine had been rewarded by the discovery of the true Cross and the Holy places:  and now the greater devotion of the Son had won a more signal manifestation of Divine approval.  The letter ends with a prayer that God may grant to the Emperor long to reign as the protector of the Church and of the Empire, “ever glorifying the Holy and Consubstantial Trinity, our true God.”  The word ὁμοούσιον, it is alleged, had not at this time been accepted by Cyril, and its use has therefore been thought to cast doubt upon the genuineness of this final prayer, which is nevertheless maintained by the Benedictine Editor Epist. ad Constantium—Monitum, § x..  The letter as a whole is certainly genuine, and the phenomenon is too strongly attested by the historians of the period to be called in question.  While, therefore, we must reject Cyril’s explanation, we have no reason to suspect him of intentional misrepresentation.  A parhelion, or other remarkable phenomenon, of which the natural cause was at that time unknown, might well appear “to minds excited by the struggle between the Christian Faith and a fast-declining heathenism to be a miraculous manifestation of the symbol of Redemption, intended to establish the Faith and to confute its gainsayers Dict. Chr. Biogr. p. 761..”