Queen Luheia was once the ruler of Skifander; the exact era of her rule is unclear, but it was long enough ago that the events connected to it have passed into legend in Skifander. She was in theory an immortal and unaging ✣ Ancient God-Queen, as is (the still living) Queen Albia of England. The two of them were able to communicate via a system of Mirrors which have since "gone dark." The mirror located in Skifander now bears ✣ Luheia's name. According to one of the aforementioned legends, passed along by Zeetha, Luheia died ✣ thwarting the nefarious plans of an individual known as the "Grey Witch". Her successors to the throne, including Zeetha's mother, were/are not immortal.
Later, Albia has An Important Realization ✣ that it was Lucrezia Mongfish killing the Queens through the Mirrors. Hence, it seems likely that the Grey Witch is yet another alias of Lucrezia.
Luheia's name appears ✣ on a plaque on display in the British Royal Observatory, written in "Ovalform 27", which is (evidently) archaic Skiff, and which no one is able to read until Zeetha comes along. The context of this mention and the purpose of the plaque have not been revealed.