And when he got to King Rion, he struck him hard with his sword, which went through his shield and hauberk, and if it had not been for the snake skin shirt he was wearing beneath his hauberk, he would have killed him; the snake skin was so hard that he could not break it or cut through it, but he still kept hitting him so forcefully that he sent him spilling head over heels to the ground.

Vulgate Merlin