When Mordred, who had no sword, had rested for a long time and watched to see what he could do, he threw his shield to the ground and ran to Gaheriet's side and took him by surprise in such a way, before Gaheriet saw what was happening, that he had thrown him down underneath him on the ground.

Then he said to Agravain, "Brother, take off his helmet and cut off his head, for if the traitor escapes this blow, we'll never again have such a good chance to kill him."

The Post Vulgate Cycle