Moonlight Shadow is a unicorn pony from Canterlot, a cleric of Luna, and an itinerant novitiate of the Ordinum Aurora. The younger of the two daughters of General Eastern Wind and Lady Evening Song, Moonlight Shadow was born to a life of luxury that has gotten a bit more complicated in the past few years.
Moonlight's cutie mark of a silvery helping hoof was the first to appear in her class (a private school in Canterlot), and shortly after it appeared, she was approached by the Temple of Luna to begin training to become a priestess, an offer she gladly accepted.
The year 1299 brought the first tragedy of her life, when her father's airship crashed during the defense of Cloudsdale, and the next year was no kinder when her sister, Morning Star, caught the trotting fever. Try as she might, there was nothing that the young acolyte could do save for easing her sister's pain. Moonlight and her mother grew more and more distant in the following years, as her mother focused more on politics and Moonlight focused on her studies at the temple.
In 1302, Moonlight began studying with the Ordinum Aurora, and began unlocking the secrets of divine magic through her patron deity, Luna. She advanced quickly through the ranks of students, and managed to mostly hide from the cutthroat environment of Canterlot politics in the halls of the Ordinum's schools.
In 1306, tragedy came a last time when her mother was assassinated by a political rival, one looking to finish the business of securing his power by eliminating those who could threaten it. The newly frocked itinerant novitiate Moonlight was warned by the High Priestess of Luna, who managed to deliver a significant sum of bits, some armor, and a ticket out of the city to her old student. With freedom in her hands and certain death laying behind her, Moonlight ran...
At least, that's the story she tells. There has to be more to it than that.