‘Helyan of Ireland’
Helyain, Helyanz, Heruanz
When Arthur refilled the seats of the Round Table after Lancelot and his followers had left, Lancelot’s seat was given to Sir Helyan. This alone suggests that Helyan was an excellent knight, at least “of his hands”.
He was a king’s son, but of which Irish king is unknown. Presumably he perished with Arthur in the last battle.