Baron Maheloas was listed among the vassal lords whom Arthur summoned to court of Erec’s wedding.
Chrétien de Troyes describes his Isle of Glass as a place free from storm, thunder, lightning, snakes, toads, and extremes of hot and cold. This sounds to me like Avalon, and Avalon is usually identified with Glastonbury; yet further on in the same passage Chrétien names Morgan’s lover Guingomar as lord of the Isle of Avalon.
Possibly an example of one place – and character? – being split into two.