Two entries with the name Avarlan.
In the Vulgate Mort Artu, a knight who hated Gawain.
He poisoned some apples, which he expected Guinevere to give to Gawain at dinner. Guinevere, however, offered the fruit to Gaheris of Carahew instead. Gaheris died and Guinevere, completely innocent, was accused of murder. Lancelot eventually acquitted her.
Malory renamed the character Pionel.
Vulgate Mort Artu | 1215-1230
Post-Vulgate Suite du Merlin | 1230-1240