When first Christianity penetrated Britain, a great number of Saints existed, especially in Wales and Cornwall. At this time there was a duke, or prince, of Cornwall, named Melian, whose brother, Rivold, revolted against him, and put him to death. Melian left a son, Melor, and the usurper only spared his life at the intercession of the bishops and clergy. He, however, cut off his right hand and left foot, and sent him into one of the Cornish monasteries to be brought up.

The legend goes on to relate that the boy was provided with a silver hand and a brazen foot, and that one day, when he was aged fourteen, he and the abbot were nutting together in a wood, when the abbot saw the boy use his silver hand to clasp the boughs and pick the nuts, just as though it were of flesh and blood. Also, that one day he threw a stone, which sank into the earth, and from the spot gushed forth a fountain of pure water.

Rivold, fearing lest the boy should depose him, bribed his guardian, Cerialtan, to murder him. This Cerialtan performed. He cut off the head of Melor, and carried it to the duke; but angels with lights stood around the body and guarded it.

On his way to the duke, Cerialtan was parched with thirst, and exclaimed, "Wretched man that I am! I am dying for a drop of water." Then the head of the murdered boy said, "Cerialtan, strike the ground with thy rod, and a fountain will spring up." He did so, and quenched his thirst at the miraculous well, and pursued his way. When Rivold saw the head, he touched it, and instantly sickened, and died three days after. The head was then taken back to the body, and was buried with it. But the relics were afterwards taken to Amesbury, in Wiltshire.