Of the many mysteries in the land of Equestria, few of them begs as many questions as those about the ones who guard princesses. I do not speak of the Royal Guard though.

I, of course, speak of the Centaurides that guard Celestia and Luna day and night.

While the Royal Guard does protect them to some extent, they only guard their residences and place where they are to appear and are the first line of defense.

But the Centaurides, they do much more. They guard the princesses' lives with their own. They are their personal guards in effect. Only Celestia and Luna can command them, and they bow to nopony but their princess.

Not much is known about them. That they are fearsome warriors none doubt, as those few stupid enough to try and kill the princesses have discovered to their doom, for their life is forfeit should they attempt to kill the princesses.

Versed well in the arts of bow and blade, they are seen as scary and unapproachable when you first meet them. Having known them now for some years, I can say that underneath that warrior mask, they can be as friendly and outgoing as any.

It is not just their skills and demeanor that leave many questions, but also their physical appearance. For while they have the lower bodies of ponies, their upper halves do not conform to any species known on Equus.

Having asked them myself, they would not speak of it. It is obvious they know what they are, but if they have told any, only they know.

Even the name Centaurides is a best guess name, for they do not speak of it themselves. Where the name comes from is also a mystery. Some say it comes from another world, but none know for sure.

There are also rumors that they and Celestia and Luna are more than just princesses and guards. But when I asked, all Princess Celestia would give me was a wink. Luna was even less help. All I got out of her was a roaring blush before she teleported away. Make of that what you will.

Regardless of any truth to the rumors, it is obvious that both princesses have the highest regard for the one who stands beside them. And I believe that is all that matters in the end.

With them by Celestia and Luna's side, I for one look forward to whatever future they make for Equestria.

From the Diary of Clover the Clever.

***

Princess Twilight wasn't quite sure what to make of what she had just read. It was an interesting read to be sure, and it was an honor to read something by somepony so famous.

But it raised more questions than it answered.

She, of course, knew the ones who protected Princess Celestia and Cadance. Luna's was more of a mystery, but she hoped that could be fixed.

Appitrite, the one who stood by Cadance, was much like her in some ways. Kind, loving, and beautiful in a way that made stallions fall head over heels for her. But she remained dedicated to Cadance alone.

Twilight knew her young age did nothing to take away from her combat ability. During the Changeling Invasion one year ago, she had lost track of how many of the creatures Appitrite had slain with her bow. When it had come to close quarters, her blades had claimed even more. Twilight had never seen anything so beautiful and yet so deadly at the same time.

And then there was the one stood beside Princess Celestia. Twilight couldn't help but gulp at the thought.

Hippothea was very much like her mentor. Regal, majestic, and not a little mysterious. She had a more rugged beauty to her than Appitrite, but Twilight could still admire it.

But that was not what stood about her to Twilight. Hippothea fought with the largest bow she had ever seen. It was so large in fact that she carried it on her equine back, unlike Appitrite, who carried hers on her upper body.

It was her work with the greatsword though that really stood out. How she could carry it was a mystery for the sword looked as heavy and was as big as Hippothea herself was, and yet she swung it like it weighed nothing more than a leaf.

Which was even more amazing seeing as her upper body was no more muscular than Appitrite's. Maybe Twilight would have a chance to ask her about it.

And that leads her back to the present. Her coronation After Party was still going on outside, but she had returned to her Guest Room some time ago, tired out from all the day's activities.

As she had been saying goodnight to her friends and family though, Princess Celestia had given her this book, saying it might make for a good bedtime read. As usual, she was right, but Twilight still had a ton of questions. It hadn't answered much about Hippothea and Dianathe, but it was a start she supposed.

One thing though stood out in her mind. Now that she was an alicorn as well, would that mean she too would soon have someone like them watching over her? She wasn't sure what to think about that. Her new status was something she was still getting used to.

And everything that came with it.

If she did though, how would she choose them? The book had never said how Celestia and Luna had, and she'd never thought to ask Cadance. For that matter, where did they even come from? How did they know when to come to Equestria? And how did they come to Equestria? So many questions, and no answers.

Twilight could only hope that would change in the future as she switched off the light, and soon passed into a dreamless slumber.

***

Across Eternities Crossing, in land only six knew of, but only three had ever seen, another journey was about to begin. Whether Twilight knew it or not, she had called out to those who would stand beside her for all time, and they had answered.

Ponyville would never be the same again in the coming weeks.

***

Hippothea and Appitrite watched the light go out in Twilight's window with interest. They too had heard the call she had unconsciously sent out, even though it wasn't meant for them. What surprised them though was how many had answered it back. Never before had so many done so.

"This is unexpected," Hippothea said after a moment. "I did not think so many could ever hear it at once."

Appitrite smiled. "Twilight is a special pony. Maybe that's why? Nopony expected Cadance to ascend either, and now look at her."

Hippothea smiled as well, but there was more to it than that. "You hope one might be as young as you, don't you?"

Appitrite frowned as she crossed her arms and stomped a hoof. "Is that too much to ask for? No matter how much you try, I still don't feel like I belong with you two."

Hippothea's smile dropped. It was a thought Appitrite had shared before. One she and Dianathe had tried to assuage again and again, but they could only do so much.

The three of them came from different times. She and Dianathe had come from a time when the world was still recovering from the Age of Fools, as they called the Three Tribes Era.

Appitrite had grown up in the Age of Enlightenment, as the new age was called. Neither of the two eldest could say what might have changed in their old home.

Once one passed beyond the Forbidden Portal, none were ever allowed to return. It was the price they paid for their service.

Hippothea wrapped an arm around her younger companion and pulled her close. "Never think you are not good enough. You have proven that time and time again. I am proud to call you sister."

Dianathe soon joined them and wrapped her arm around Appitrite's other shoulder. "As am I. Though you are young, that does not take away all you have done."

Appitrite couldn't help but blush as her tail flicked back and forth. No matter how many times she heard it, the praise of her elders was something she could never forget.

Together now, the three of them stood there, sisters in all but blood, as their thoughts turned to the future and what it might hold for them all.

Author's Note

To be clear, this is a crossover with Disney's Fantasia. Namely the Pastoral Symphony segment. Aside from now being native to Friendship is Magic's universe, they don't look any different.

The names for Celestia, Luna, and Cadance's are all based on names from Greece. I felt it fit them since Fantasia had them set there in the film.