Who is Meleagant from Arthurian Romances and what is their importance?

Meleagant arrives at King Arthur's court and announces that he has many of King Arthur's knights, ladies and maidens imprisoned, and that he will not release them for any of the king's money or power. He does, however, challenges any of the king's knights to defend Queen Guinevere in order to release his prisoners. He defeats Kay, and then he takes Kay and the queen prisoner. When he refuses to surrender Queen Guinevere to Lancelot, the two battle and the knight and is defeated. Meleagant finds blood on Queen Guinevere's sheets and accuses her of sleeping with Kay. He battles Lancelot again, who acts as Queen Guinevere's champion in the charges. He is defeated again, and the battle is postponed. Meleagant secretly has Lancelot imprisoned, eventually in a tower on an inlet. He travels to King Arthur's land for battle, but he does not find Lancelot and Sir Gawain offers to stand in for Lancelot one year hence if Lancelot is still missing. Meleagant returns to his father, bragging that Lancelot is afraid of him, but his father does not believe him. He returns to King Arthur's land to battle Sir Gawain but is shocked to find Lancelot escaped from the tower. Lancelot defeats and kills Meleagant.