What evidence is there that the Image of Edessa had bloodstains?
On August 15, 944, the image-bearing cloth of Edessa arrived in Constantinople. Gregory Referendarius, the archdeacon of Hagia Sophia, Constantinople’s great cathedral, delivered a sermon on the day after its arrival in which he described the cloth as having the likeness of a man, formed, it seemed, through sweat and blood. This was a clear indication that the cloth contained bloodstains.
This is important because a significant amount of evidence supports the theory that the cloth once in Edessa, now in Constantinople, is in fact the Shroud of Turin. A reference to bloodstains help to confirm this theory.