Two entries with the name Elias.
Le Bel Inconnu | Renaut de Bâgé, 1185–1190
The leader, a captain, of the Sessoins and “a good man of arms”. Elias commanded an invading Saxon host against King Mark of Cornwall. Elias led his man nobly in battle before Tintagil. Mark was forced to send for Tristan to assist in repelling the invasion. After Tristan led a battle against Sir Elias and destroyed much of Elias’s force, Elias offered to fight any knight Mark could offer, one-on-one, to decide the conflict. Whichever side lost would have to pay an annual tribute to the other side.
Tristan met Elias in the challenge. Elias proved to be an excellent knight, as good as Tristan, and it was only thoughts of Isolde that caused Tristan to win the battle and to mortally wound Elias. Tristan remarked at the end,
Sir Elias, I am right sorry for thee, for thou art a passing good knight as ever I met withal, except Sir Lancelot.
With Elias dead, Mark took prisoners and sent the rest of the Sessoins back to their own country.
Prose Tristan | 1230-1240
Le Morte Darthur | Sir Thomas Malory, 1469-1470