Pinkamena Diane Pie, Captain of the Royal Guard.
 
An unlikely choice by Queen Solar Flare, Pinkamena Diane Pie is the first earth pony ever to receive the honor of Captain of the Royal Guard. Born and raised near the once Crystal Empire, Cpt. Pie grew up on a rock farm with her mother and father, Cloudy Quartz and Igneous Rock, and her sisters Maud Pie, Limestone Pie, and Marble Pie. Cpt. Pie lived on the Rock Farm for most of her life until her late fillyhood, when she volunteered for the Equestrian Defense Force when the Changeling Army attacked. There she gained her cutie mark for defending her country, a stone sword and shield.
 
Impressed by Pie’s loyalty and bravery in the EDF, Queen Solar Flare offered the young mare a spot in guard as a trainee, as she was not entirely a seasoned soldier. She grew quickly into the ranks, if not popular but feared and respected. Pie did not have friends, nor any sense of humor. She grew into her role as the Captain, with absolute authority over her subordinates.
 
Captain Pie is acquaintances with Ambassador Sandwich, but has no feelings of friendship nor romantic notions towards him or anypony else.
 
Captain Pie has little interest in anything other than her job and pleasing the Queen.
 
Captain Pie remains in contact with her family in the Rock Farm.
 
[This is an AU, if Celestia had become paranoid that her sister was seeking higher power and quickly grew into insanity and banished her sister to the moon. Celestia is now a tyrant and rules Equestria with an iron hoof, and seeks to dominate the world. The sonic rainboom never happened, and the main six have not met just yet, and are not the Elements of Harmony.]