Mention in The Travels of Sir John Mandeville
"At Constantinople is the palace of the emperor, right fair and well-dight: and therein is a fair place for joustings, or for other plays and desports. And it is made with stages, and hath degrees about, that every man may well see, and none grieve other. And under these stages be stables well vaulted for the emperor’s horses; and all the pillars be of marble.
And within the Church of Saint Sophia, an emperor sometime would have buried the body of his father, when he was dead. And, as they made the grave, they found a body in the earth, and upon the body lay a fine plate of gold; and thereon was written, in Hebrew, Greek, and Latin, letters that said thus; Jesu Christus nascetur de Virgine Maria, et ego credo in eum; that is to say, ‘Jesu Christ shall be born of the Virgin Mary, and I trow in him.’ And the date when it was laid in the earth, was two thousand year before our Lord was born. And yet is the plate of gold in the treasury of the church. And men say, that it was Hermogenes the wise man."