He was warring against a defenseless countess, (called the Lady of Noroison in Chrétien’s Yvain), when the latter and two of her damsels found Yvain, whom agreed to help in return for her healing services.
Little is sais of the whys of this war: Alier would appear to have been the aggressor, and he managed to burn some of the lady’s buildings before Yvain conquered him; but he was allowed to surrender and swear to repay and rebuild her losses as far as possible.
Yvain, or Le Chevalier au Lion | Chrétien de Troyes, late 12th century
Ivens Saga | 13th century
Ywain and Gawain | 1310-1340