Princess Celestia

Princess Celestia is a white Alicorn. She is Co-Ruler of Equestria with her sister Luna, and the loving teacher of her Faithful student, Twilight Sparkle.

Duties
Celestia is charged with raising and lowering the sun. In Luna's absence, she raised and lowered the moon as well. Being the elder of the two sisters, she takes a more protective, motherly role in leading her subjects; many times over the millenia, she has sacraficed her own happiness for the sake of her ponies safety.

Current Role in Story
A moral figure. Celestia herself is currently in hiding, only a select few are aware of her location.