Twilight has been having her study sessions with the Cutie Mark Crusaders for some time, and has been remarkably pleased with their progress. And kind of worried, as they keep getting better and better. She might be a princess now, but TEACHING THE CUTIE MARK CRUSADERS? She'd rather not become their formal mentor. Yet.

A letter is sent out, and Princess Celestia gets a call for help. And, an opportunity is born. After all, why not? After a thousand years, perhaps it is time to do something else, just for a bit. She does have a rather wonderful younger sister who hasn't been ruling a land for a thousand years, and who has been studying how to rule for the past four rather intensely. So, teaching three fillies undercover? Sounds like fun.

And Luna. She's wanted to be as respected as her sister so much that she once went mad over it. But now, she's simply being handed the power that she once coveted for so long and no longer wants. What kind of a world does she live in now that her highest desire has been so casually granted?

With all of this, What Could Possibly Go Wrong?

Arcs:

Escape: When Celestia hears the call, she jumps at the chance to teach again, especially three fillies who might surpass her grandest student. But first she's got to escape her own identity...
Examination: So you want to find out what a filly does? Time to test her silly, so long as you don't taunt the Happy-Fun Filly.
Excitement: So, you've found the Happy-Fun Filly. Great, but the other two need help as well, and Scootaloo has this ~Great!~ idea for how to use her new-found magic...
Encouragement: Cometh the Bubbles, and a whole load of new headaches as they find out just what being a Happy-Fun Filly really means...
Exaltation: Where's Luna been this whole time? She can't be very happy about being left in the lurch holding Equestria. She could really use somepony to talk to.
Exercise: 'Sunbeam' is looking to teach the Happy-Fun Filly more, but first she needs to start taking care of the wagon-tire she keeps around her middle so that certain Unfun-Time Fillies don't interrupt her. And there's this big draft stallion looking for help...

Diamond Tiara has always enjoyed picking on the Cutie Mark Crusaders. But one day, she finds she's gone too far, and everything for her comes tumbling down. But help may come from the most unexpected of places...

Started before season four, and does not take season four canon into account.

This story is 100% Diamond Cutters Approved!
Note: If reading this inspires you to write your own Diamond Tiara fanfics with similar premises, send me a link, as I'd love to see them.

Side Story to The Demesne of the Reluctant Twilight Sparkle

When Doctor Princess Twilight Sparkle got Ponyville and the surrounding lands as her exclusive demesne, she knew it meant changes and stuff. Glittering opportunities. Dire crises. Friendships gained and imperiled. The dawn of a new age for Ponyville. A renaissance of the arts and sciences. A great test of her abilities as a leader and as a friend.

The brewing civil war took her by surprise, on the other claw.

The Princesses and their allies in Canterlot are working to change the laws, disband the new militias and ensure a lasting peace, but they need time. Soon, this cold war of arms and intimidation will heat up, and all the laws and decrees in the world ain't stopping it.

Doctor Princess Twilight Sparkle will buy them time. She will do what it takes to keep her friends, her family, and yes, her demesne safe.

With the help of a handsome griffon security professional—that's me, by the way—a devious illusionist, a ruthless athlete, a bored noble, and a pair of boater-clad con-ponies, she'll stop the damn war herself if she has to.

Touch wood I'll live to tell about it...

Pinkie doesn't tell ponies about Pinkamena and Surprise. The doctors said that they were bad for her, that they were a disease, but she disagrees. Sure, Pinkamena's a bit of a grumpy-pants, but she's still a great friend! She's often the voice of reason to counter-act some of the other two's crazier ideas, after all. Surprise, on the other hand, is a great prank-player, and always up for some fun. She's more like Pinkie, only more hyper. Both are great fun to be around, and they get on well.

Thing is, she knows that if she told ponies about them, then they would be dragged back to the hospital. And then be 'treated' again. None of them want that. Because of this, not even her best not-in-head friends know about them. The three of them have, for years now, been careful enough to keep the existence of Pinkamena and Surprise secret.

This has, of course, gone out the window now that Twilight is hammering on the door after overhearing one third of a conversation, with no sign of anyone else talking.

Hints of F/F shipping inside. Nothing will actually come of it here, though. Maybe in a future story.

Cover art can be found here: http://killryde.deviantart.com/art/Smile-338206490

Long ago, Celestia sealed her sister into the moon. Her subjects, however, began to fear her and the elements she wielded, seeing they could be used on anypony. Heart broken, she fled her kingdom, leaving it to the ponies who inhabited it.

A thousand years later, Equestria is predominantly under the control of Earth Ponies. Industry thrives and magic is considered a thing of fantasy; Big Macintosh always thought this himself. However, his life is soon to turn around, and he will find himself on an adventure like no other.

(The main picture might be subject to change; just trying to paint a portrait of what kind of era the ponies are in in this alternate world)

(REBOOTED FOR GREAT JUSTICE)
(Proof-read by Sage-Wolf)

(Made the feature box. Awww riiight!)
(Well that was certainly short lived!)

Mis-communication has started many a war, but in this case maybe calling it a war was too generous.

The "war" is over, Twilight has successfully orchestrated a bloodless end to the Griffons' aggression, but only now does she realize that there is more to winning than she had first assumed, especially against a nation that holds war as a central part of their culture...

Now Twilight must deal with the aftermath while facing a challenge she never anticipated: being seen as a conqueror.

This can be read alone, but I recommend reading the letter that started it all for a chuckle and a little exposition. This series of expositional one-shots can also give some additional world-building.

This story is a sequel to The Monster in the Twilight

Now that Luna has returned to the throne, and the aftermath of her brief appearance as Nightmare Moon is being cleaned up, the story is over. Right?

Not quite.

Twilight Sparkle had nearly been destroyed in the chaos of Nightmare Moon’s return, but now with the assistance of her five friends, she is facing a fascinating new world filled with wonderful things. No longer the scarred monster who nearly destroyed Canterlot and raged through the Everfree Forest for over a decade, now she has been healed by the Elements of Harmony and is living at the edge of town with her adoptive mother Zecora. Not all the fears of her past can be left behind that easily though, and now she must face the consequences of her actions as she faces the most daunting challenge of her life.

Ponyville.

Letters is a sequel to the alternate universe story The Monster in the Twilight. In this story, Twilight Sparkle exchanges letters with Princess Luna, two ponies with a common problem of fitting in and making friends after the destruction of Nightmare Moon.

Normally I would try to talk you into reading the sequel even if you haven’t read the original story, but in this case, you’ll probably be more confused than entertained. But go ahead. I don’t mind if you don’t read the first story. You’ll never find out what an Urlock is, but that’s fine. It’s your funeral.

Editing Assistance by Alicorn Priest, Peter and Tek

Credit for the incredible picture All Night Study Group goes to Bibliodragon at Deviantart

Physical books are available on Lulu.com (up to Chapter 82)
Letters From a Little Princess Monster (Paperback) 726 pages
Letters From a Little Princess Monster (Massive Hardback) 780 pages

Diamond Tiara Rich- wealthy, beautiful, spoiled rotten. Everypony hates her, but at the same time, they desperately want her life. But this life doesn't come without problems.

Diamond Tiara has always hated Apple Bloom, and who could blame her? She's annoying and pathetic and obviously insanely jealous. So anytime they see each other, Diamond tries to get it into her head that she, being rich and amazing, is way better. But after a particularly dicey encounter with her favorite victim, Diamond makes a mistake.

And that mistake sends her to boarding school.

Determined not to let her new circumstances get her down, Diamond vowed to have the entire school eating out of her hoof by the end of the year. But that's a little hard to do when the role of resident Queen Bee has already been filled...

But unbeknownst to anypony, strange forces are lurking close. A student hungers for power, and secrets of Equestria are revealed. Soon, it will be up to Diamond to decide what matters most- herself, or the ponies around her?

Takes place right after Call of the Cutie.

Cover art by Kikirrikitiki on DeviantArt.

Smaug is the mightiest of all beasts in Middle Earth. No creature can match his prowess. As the last of his kind, he has no obligations to anyone being other than himself. The only thing he cares about is his hoard.

But this new creature, this alicorn, may just change that.

Be Awed and Amazed by the tale of Sweetie Belle as she traverses the multiverse in search of her lost mentor and friend, Twilight Sparkle! Will she find her in post-apocalyptic Equestria? Or maybe in a strange world where everypony is the wrong gender? Or even where a Pony claims to be a human? Read as she journeys through very familiar worlds you might have read about... if you dare!

At this point in time all the main worlds to be visited have already been chosen. Thank you all for the suggestions, and I hope you enjoy the surprises!

Here's the official TSC:F Music Intro: The Sweetie Chronicles: Fragments

WDTP: S2/3-CE
You can also visit the TV Tropes Page which has spoilers!