The sun, the moon, and the stars.
Each a worshiped, extraterrestrial, being. Each portrayed in centuries of art, music, literature, and theatre.
In Equestria, the princesses are affiliated with these celestial bodies. Princess Celestia with the sun, and Princess Luna with the moon and stars.
That's how it's always been, since ponies started taking records. But what about before they started?
Celestia and Luna were born to King Cosmos, and Queen Galaxia. Princess Cadence and Twilight were created alicorns, from their original pegasus or unicorn form. Together, they rule Equestria and the lands beyond in wisdom, love, and harmony.
Only two know that there was a fifth.
He was lost to time, only found in the most ancient of records, kept in the darkest vault, in the most secret of places in all of Canterlot. Buried deep beneath the Canterlot Archives...
His name was Prince Midnight Star.
He ruled the stars. He shaped thousands of suns that were of Celestia's, or so much larger, into art that would inspire ponies for generations, that would make them yearn to learn more about what was beyond Equestria. Stars, that would guide them to new lands, to explore and create. Stars, that gave the ponies at night, a show with the moon that would be unique and unforgettable each night. Stars, that earned him a love that was so powerful, it could've repelled all evil, shown a light in even the darkest places, and brought forth an era of peace and prosperity that could've lasted forever.
And then he left. He disappeared, into the shadows. Not in control of the stars, but always watching.
The Princess of the Moon became the Princess of the Night, and she took the responsibility of the stars.
The stars never shown as bright as they had when he had them.
Eventually, Equestria moved on. Ponies forgot of the shows of the night, of the benevolent ruler. Truth turned to rumor. Rumor to myth. Myth to legend. Legend...to nothing.
However, it is well known that alicorns never die. He has watched Equestria grow, from tiny settlements on the fields, to great cities on mountains and islands.
He watched as ponies no longer flew or galloped across the land, rather they traveled in elegant airships, speedy trains, or recreational helicopters.
He watched as ponies no longer watched the night sky, rather they frolicked mainly under Celestia's sun.
He watched as Equestria lost one of it's most dear princesses...and watched as she returned as Nightmare Moon, only to be defeated by the Elements of Harmony yet again.
He watched as Discord reigned chaos all over the land. He watched as a royal wedding was interrupted by an evil hive of shape-shifting changelings.
He watched the Crystal Empire rise anew. He watched a new princess rise from the quaint town of Ponyville.
He watched the Everfree Forest tried to take hold on Equestria. He watched as a long past enemy returned and stole magic from all species of pony. Not him though. He was careful. He watched as a new castle emerged from the ground of Ponyville.
Yet no one knew he watched.
He knew that the sisters knew that he was still probably alive. He knew he had caused them great grief by leaving.
But he had his reasons. Whether they knew them, he didn't know.
But he was tired of watching. Tired of standing on the sidelines, not doing anything.
And he oh so missed his stars. His beautiful stars...
Hey, if Luna could return after millennia, surely he could.
Right?