This story is a sequel to Princess Celestia The Changeling Queen: Stories Behind the Mask

At the Royal Wedding, Chrysalis and the Changelings were revealed to all of Equestria.

But another mask was torn away that day. A mask born for a thousand years. A mask created on one promise. A mask, that has become synonymous, fused, to its bearer.

A mask that when ripped off, causes Twilight, her friends and Luna to question everything they ever knew about the one pony, one very important pony.

At the Royal Wedding, the meaning of the phrase 'Princess Celestia' changes forever.

NOTE: Chrysalis is NOT Celestia!!! That'd be impossible to pull off.

Credits to: Plainoasis for the design of the cover art
Note 2: Original cover art here: https://angelea-phoenix.deviantart.com/art/Contest-entry-Changeling-Celestia-337023552

Pre-read/edited by Zervziel,
Blankscape,
FinalFan,
Courage Fire
Aurora Borealis

Side Stories to this can be found: here.

An audio-reading on youtube up to Chapter 21 is up by StraightToThePoint Studios. I'm aware there are others but this is the nearest complete one: [embed]https://youtu.be/X3eMW673CSY[/embed]

There are also 2 print versions of Princess Celestia:The Changeling Queen. Nonexistent Publications run and Ministry of Image's run.

Contribute to the TV Tropes Page (thanks to Babs_Seed72 for getting it up)

Earth pony, pegasus pony, unicorn; a human entering a Conversion Bureau will end up as one of these three pony forms. But there is a secret provision, to which all Bureaus must adhere utterly, should one unlikely but intolerable transformation somehow occur. The absolute monarch of Equestria fears nothing from the human world. Nothing save this. Lillian Fogarty wanted only to be a simple pony in Equestria. Sought by the combined forces of Earth's corporate government and the might of Equestria itself she finds herself an abomination in both worlds, her survival almost certainly an impossibility.

♥ As Featured On Equestria Daily!

This story is a sequel to Harmony Defended

Ten years ago, Equestria was nearly destroyed in a combined invasion of its worst enemies. Only with the timely intervention of its erstwhile human allies was the nation spared slavery and extinction. The war is over now, and the treaties of peace faithfully followed even after a decade. While earth ponies help rebuild Earth's ecosystem, human tractors erect roads and cities with terrifying speed.

Sweetie Belle helped make victory possible, but the cost of that victory was one of her best friends. Equestria is safe now, and ponies are spreading to the stars. Why doesn't she feel happier?

Pinkie Pie wakes up in a mental institution to find that here entire life in Equestria has all been a delusion, now she's cured of her "illness" but still has no idea who she is or what her real name even is. All she has now is a empty bottle of sarsaparilla, with a crumpled up birthday card inside, and an address..........

This story is a sequel to My Little Apprentice

The summer sun celebration brought the filly Second Chance into contact with one of the most powerful beings in Equestria, Discord. Thanks to him, she's got all her memories back, and has access to the powerful Jebr Stone. Will that be enough to save her dying species without sacrificing Equestria in the process? Nor is she the first traveler from her world to reach Equestria, or the only one with plans for it.

Will Chance's newfound friendships be enough to keep her sane and preserve Equestria through the dark times ahead?

Continued in MLA: Perihelion!

As usual, a huge thanks to Zutcha for the excellent cover, this time with shading!

This story is a sequel to MLA: Perihelion

It's been a handful of years since Twilight came into her own as a Princess of Equestria, a few years spent in peace and harmony without so much as an angry spirit or clandestine invasion to take away from the tranquility of Equestrian life. Unprecedented developments in the technological and thaumaturgical sciences seem to be preparation for something, though nopony realizes what that something might be.

Nopony except the Princesses, who have not failed to see the signs of impending disaster that began with the mass kidnappings just following the Summer Sun Celebration. When all their preparations are turned upside down, can an alliance with the mysterious Precursors turn the tides of the most devastating war in Equestrian history, while there is still anything left to save? Enemies and allies appear in the most unlikely of places, and friendship with a dying elder race can be more dangerous than an invasion of Dragons and Changelings. What is a pony willing to give in defense of harmony? What are they willing to sacrifice?

This story now has a companion piece, The Sunset Campaign! This story is designed to bring Harmony Defended more into line with the three-story version of My Little Apprentice. If you read Apogee and Perihelion, you may want to read that as well!

This story was written prior to season five, and as such any events which transpire therein may or may not be treated as canonical. All events up to and including "Twilight's Kingdom" are treated as having occurred, however.

A huge thanks to my Alpha Readers! Thanks to these wonderful people, new chapters aren't nearly so riddled with mistakes and errors as they used to be. Thanks to Sparktail, TwoBit, Withered Pyre, and Zutcha. Zutcha of course deserves double the love, since he's also the artist of the cover and any other fantastic art that finds its way into the story.

This story is a sequel to Steel Solstice

Continued in: My Little Apprentice: Apogee

Twilight Sparkle learns that the trust and goodwill of the Princess isn't always a good thing as she's given the trust of an important assignment. When that assignment turns out to be long-term, how will she handle taking care of a filly of her own? How will she handle this strange new filly, who proves to be much more than she appears. As a matter of fact, she seems to be from an entirely separate universe.

Meanwhile, Second Chance has kept only enough of her memories to know that she isn't what she should be. The wonderful world of Equestria has its own dangers, and she seems to have a knack for attracting trouble. The more of her memories return, the more she wishes she could just forget. But you can't forget when all of Equestria depends on you remembering.

Only one thing's for sure: The longer Twilight keeps this strange filly in her care, the stranger her own life will become, and things she thought she knew about Equestria will unravel before her eyes. Strange ancient devices, an eccentric mint unicorn and her so-called "Equestrian Precursor Society" are only the beginning for Twilight Sparkle as she begins a journey of her own. She too may wish she could simply forget. Unfortunately, it's too late for either of them.

One ordinary mare. One never-ending time loop. Infinite ways to die.

How long before she snaps?

This story is a sequel to Stardust

Times are changing for Equestria as Twilight’s return brings with it news of people and cultures from beyond the peaceful world everypony knows. Aid and volunteers are freely offered to help the besieged humans of Earth because every Equestrian knows that’s what good friends do. Unfortunately, making friends can also have the unintended consequence of making enemies.

When the monsters besieging the humans strike at Equestria with a level of brutality not seen in over a thousand years, the cry for help is sent to all the kingdoms of the world. Honored allies step forth to fulfill ancient treaties and oaths. Enemies, old and new, bury their grievances. An alliance never before seen in Equestria will be created to combat the monsters from the void.

And because of these events, a grim but welcome sibling to the XCOM project is born.

(XCOM/FiM Crossover)
(Sequel to Stardust, which I recommend reading before starting this. Fortitude Amicitia and Broken aren't required reading but are supplemental to the storyline)
(Gore tag for blood and violence)
(Alternate Universe tag because of the divergence from canon that Stardust has caused)
(Uses elements of Season 4)
(Coverart produced by the amazing Carnelian!)
(Many thanks to Arzoo, BradTheBrony, Vandenbz and Setokaiva for prereading!)
(As of 03/07/2016, the prereading team consists of Arzoo, BradTheBrony, Noble Cause and Metallusionsismagic!)
(Complete with it's own TVTropes page as part of the Stardust continuity. Could use some updating!)
(Character tags will be added as chapters are added!)
(Featured 5/12/2014! Thanks folks!)
(Possible spoilers in the comments! BEWARE!)

On a patrol through the White Tail woods, Twilight comes across a dying changeling. Torn between giving up the drone to the guards or leaving it in the inhospitable wilds, Twilight reluctantly takes the drone in. As it awakens she realises that the drone was a blank slate, with no connection, no 'programming' guiding its functions. So Twilight sets out to teach this changeling about the world, one hoof step at a time.

Rated Teen for slightly mature themes involving ethical dilemmas.

If Word Worthy stopped editing for me, I'd likely wind up as a grammar-less hack. Thank you, thank you, thank you!