To outward appearances, Celestine was born as a servant's daughter in a powerful Duchess' household, but very few knew that she was actually the Duchess' daughter born out of wedlock. This secret was meant to be kept from Celestine, but through means unknown she was able to not only identify the Duchess as her mother, she also discerned her father's identity: a rich merchant who had passed away many years before.
It soon became apparent that Celestine had a rare gift: the ability to see things beyond what her earthly eyes revealed to her. This ability was a closely-guarded secret until a servant betrayed the Duchess and let it slip to the king's councillors. Celestine was then brought before King Leandro and asked to divine the intentions of his enemies. Instead, she foretold the coming of the Demon War, brought upon by the King's own folly, and his death at the hands of the demons themselves.
Outraged, the King immediately ordered Celestine's eyes burned so as to prevent her from "seeing" further blasphemies. The Duchess was stripped of her titles and holdings, her estates put to the torch, and what servants were unable to escape were executed. Celestine was tossed in the deepest dungeon cell of Castle Valence.
Despite her imprisonment, Celestine grew fond of her guards who, in turn, treated her as fairly as they were allowed. One day, she warned of a coming plague that would hit the outskirts of Valenthia. Upon hearing this, one of the guards moved his family into the city where they would be safe and, sure enough, a plague swept through a number of villages and wiped them out, among them the village of the guard's family.
The guards decided in secret to spirit Celestine away, telling no one and maitaining the illusion of her imprisonment by continually bringing food to an empty cell. She was brought to a Boon Sister convent, made to swear the Oath of the Boon and given a new identity. On the night of her egress from the dungeons, the Celestine constellation was brightest, a constellation most associated with portents and omens. It seemed the most fitting.
To this day, Celestine continues to have visions, but rare is the occasion where she shares what she sees.