The castle ruled by Galagandreiz.
It was inherited by Galagandreiz’s daughter after he died fighting Lancelot. The knights of the castle, and the daughter, recognized Lancelot as their new lord, but Lancelot left after a short time.
Moreiz may be a variant of Moray or the forest of Morrois in Scotland.
Source
Lanzelet | Ulrich von Zatzikhoven, c. 1200