A High Priestess is part of a specific Caste of Female Blood .
In the opening of each of her novels, Anne Bishop describes a Priestess as: a witch who cares for altars, Sanctuaries, and Dark Altars, witnesses handfasts and marriages; performs offerings; equal in status to a Healer and a Prince.
A High Priestess is a woman of rank within this caste and will normally be put in charge of other Priestess, organizing and distributing duties and jobs.