In Perlesvaus, the lord of the castle of Ariste and the land of Amorave. He made a gruesome habit of marrying women and beheading them around their first anniversary.
His cousin, the Lord of the Fens, was killed by Perceval, so Aristor decided to take revenge.
First, he kidnapped Perceval's sister, Dandrane, intent on forcing her to marry him. Then he murdered Perceval's uncle, Pelles, and killed the Bold Knight, a friend of Perceval's.
Perceval journeyed to Ariste and defeated Aristor in combat. He decapitated the wretch, and happily presented his head to Dandrane.