During the Iconoclast Period, several soldiers had taken an icon of Saint George and thrown it into a fire with other icons. When the fire had died, some bystanders saw that it had not consumed the icon of Saint George, but had damaged only a small portion of it. One soldier ran his sword into the face of the Saint. Blood emerged from this spot. The soldiers were so frightened that they ran. Some Iconodules who witnessed this miracle, took the icon to protect it from the soldiers in case they returned.
They took it to the shore and placed it into the water. Then they prayed to the Saint to guide his icon to a place where it would continue to perform miracles. The icon landed at the Monastery of Xenophone on Mount Athos. The blood stains and the burnt clothing of the Saint can still be seen on the icon.
(taken from: http://www.stgeorgecharleston.org/stgeorge.html)