Believe it or not, photocopying one’s butt used to be a form of conspicuous consumption.

A few years into Celestia’s and Luna’s reign, well before the rise of Nightmare Moon, visual duplication spells of any sort were still monumentally rare, and those that were known were of monumental difficulty. Monumental difficulty meant monumental expenses if one wanted to have a wizard of monumental skill perform one of those spells. Monumental expenses meant one only had something magically copied if it was of monumental importance. (Monumentality was quite common in the Classical Era.)

That all changed when Duchess Iridescence did something — history has forgotten what, exactly — to monumentally annoy Baroness Auburn. Many historians presume the “something” was related to wealth, the usual method of compensation among nobility, as Auburn’s response was so pointlessly expensive that it was only reasonable (neigh, thinkable) if she were doing it to show off how much money she had: Auburn mailed Iridescence a reality-perfect image of her butt. Your ancestors’ tax bits at work.

Iridescence responded in kind, but as Auburn had sent it first, it wasn’t as cheeky. Other nobles jumped on the bandwagon, and soon, butt-mailing became shorthoof for, “I’m so rich, I don’t even have to be there in person to express my displeasure.” However, as all writing had to be done by hoof and horn at this time, butt-mailing rapidly became overused by the kind of nobles who’d rather spend five minutes and ten thousand bits (back before inflation, when that was real money) making a posterior picture than twenty minutes composing and writing a succinct “screw you”. As such, butt-mailing degenerated from a crass, expensive method of showing disapproval that had some clever layers to it into a crass, expensive method of showing disapproval that wasn’t clever in the slightest. Nobles may or may not have started using it “ironically” as “satire” of their peers, proving that they don’t know the meaning of either of those words.

An unintended side-effect was the sudden crash of the insult industry. Insults in the Classical Era are so flowery because nobles employed writers to compose the most extravagant, roundabout, poetic insults they could muster to show off the thesaurus-reading capabilities of the writers they could hire (or, at least, it would have been like that if thesauruses had been invented yet). The more words employed to say “your mom’s fat”, the better the insult. Given the overall tone of Equestrian nobility at the time, this created a thriving economy of writers who, while asleep, could compose better insults than the rest of the world today. With butt photocopying the norm, nobles no longer had any reason to hire these writers.

But once these writers were out of work, they found their way into towns. Depressed from their lack of work, they followed the instincts of writers everywhere and everywhen and got drunk. Drunk ponies say rude things. And as these ponies wrote insults for a living, they got very rude. Records exist of ponies so drunk they could barely stand up straight who nevertheless delivered five-minute soliloquies on a whim of how much everypony sucked but them. No, not like today’s, these were well-written. Soon, writers began running into one another, spouting grandiose insults back and forth, giving birth to flyting (the great-great-granddaddy of rap battles). Although violence remained astonishingly low (rather than cutting implements, bruised limbs, and broken bones, fights between writers involve cutting remarks, bruised egos, and broken pride), it quite annoyed ponies to have their crude drinking songs routinely interrupted by Shakespinto-level dialogues that could last for thirty minutes. Chief among these miffed ponies was a drinker and aspiring metalsmith named Gutenbocken. Already thinking of a way to create copies of texts quickly, Gutenbocken rapidly became so annoyed with the influx of insult writers that he was inspired to work harder than ever at his creation, so he could distribute papers among the populace explaining just what in Tartarus was going on and how to put a stop to it.

In short, butt photocopying may have stimulated the development of the printing press. And you thought you were just wasting time and being annoying.

Once Gutenbocken’s printing was in full swing and pamphlets decrying the practice spread, public opinion, already quietly against the nobility and butt delivery, turned vocal. Some fiefs pooled what little funds they had to hire insult writers to attack their own lords and ladies. As the peasantry began turning out classy, dramatic insults while the nobility wallowed in stuffy old pics about the buttocks, nobles finally began realizing that doing the same thing as everypony else wasn’t clever (making them smarter than many ponies today). Gradually, the balance shifted; butt copying died down, the nobles rehired the writers, and everything was just peachy again.

However, it still remained among some of the less stuck-up nobles (yes, those do exist) as a not-serious insult between friends. Aiding this was increased ease of use of the spell in question, lowering expenses and letting it be used more frequently with the same amount of money. Even Princess Celestia rubbed (a perfect copy of) her butt in her friends’ faces every now and then. The primary exception was Princess Luna, who — being a Serious Pony with Serious Responsibilities — refused to take place in such whimsy. (Records of dreams of the time say you could tell when Luna had entered yours, as everything started to make a disappointing amount of sense.) Although she did not campaign against the practice itself, she never engaged in it to any significant degree and was quite dismissive of it.

Perhaps, given time, butt copying would have petered out again and been reduced to a quaint gluteal footnote in Equestrian history, had an Equestrian postmaster not, to use an academic historical term, totally screwed the pooch and gotten two addresses mixed up. A small-time noble with family in Canterlot was quite confused when she received a letter confirming the treaty that had been hammered out between Equestria and the fledgling Griffonstone. Meanwhile, the first griffon monarch, King Grover I, was ready to see Equestria’s response to the treaty his diplomats had worked tirelessly on and instead received a pony’s butt. It wasn’t even Celestia’s.

Needless to say, he was rather peeved.

An ordinary king would have perhaps sent a scathing letter back to Equestria demanding an explanation, upon which Celestia would realize what had happened, give that explanation, and send her sincerest apologies back, possibly with a custard pie (which, given her custard pies, would have been more than sufficient reparations. Trust me, I’ve tried them). However, Grover was Griffonstone’s first king, and so griffons were new to the whole “monarchy” thing. Grover handled this the way any griffon would have: taking on a cadre of big burly bodyguards, going to Canterlot personally, pounding on the gates, and challenging Celestia to a duel to reclaim his honor. (Nopony said he was a smart king.) Perhaps, when Grover and his griffons were escorted to Celestia, she would have realized, explained, apologized, doled out pies. Again, fate conspired against Equestria; having arrived in the middle of the night, Grover and his griffons were escorted to Luna, not Celestia. And you all know how Luna felt about butt copies.

Grover loudly and emphatically declared his reason for being in Canterlot, his desire to find the pony responsible, the lack of wedlock between their parents, and precisely where he would stick the spear he was currently toting. However, he neglected to mention that he was expecting confirmation of the treaty at the time, only that he received a picture of a pony posterior in the post. Luna was aware of the treaty, obviously, but without a mention of it or the expanse of experience she now has, she failed to connect the dots and make the right picture. She disparagingly explained the practice of butt mailing, spoke of it as a language of insults, but added that Grover obviously had somepony in Canterlot who liked him. After her earlier words, Grover took this as sarcasm and stormed off, declaring he’d see Celestia in the morning.

It was only then that Luna put two and two together and got four (it’s ambiguous whether she got to four via 2 + 2, 2 x 2, 2², ²2, or one of the other hyperoperations) and realized she’d made a bit of an oops. She’d explained to Grover he’d been the recipient of an ancient practice of insults when their two species were right on the cusp of forging an alliance. But right when it looked like the only way she could avoid the fallout was to run away from Canterlot and invent the circus so she could join it, she spotted the way out. And for that, all she needed was the best mages around, a literal ton of sheep, several hundred gallons of water, dozens of thousands of bouquets of woad, every seamstress she could muster, and a time-flux spell. No pressure.

When morning dawned, Celestia noticed a tapestry rolled up above the doorway to the throne room, before Luna charged in and explained the situation. Historical records indicate that, after a moment to think things through, Celestia gave a scream like a little filly that has never been rivaled since. Luna assured Celestia that she had it under control, and Celestia just needed to delay Grover for ten minutes or so. She was on top of things, and would have loved to stay and help her sister, but since she was the one who had told Grover about copying butts in the first place, he associated her with crude insults and indifference, which isn’t the greatest thing to be associated with when you’re a diarch. Luna teleported out seconds before Grover and his retinue barged in, leaving Celestia to face somepony else’s music. And the orchestra hadn’t even finished tuning yet.

Not fully experienced in ruling, an unprepared Celestia stammered her way through the meeting while Grover, not caring the slightest for decorum, went into highly colorful detail about the way Celestia’s family tree was a straight line, as well as other things that, to keep the standards of decency, shall not be even glanced at. Much brandishing of spears and claws ensued, even in the presence of the newly-formed Royal Guard, which only drew further attention to how their standards of entry amounted to “can frown kind of menacingly, but don’t hurt their feelings” (in other words, not much change from today). For better or worse (hint: the first), Grover’s ranting and raving used up Luna’s allotted time, and at just the right moment, he turned to storm out, leaving behind deathly warnings and maternal insults for Equestria.

Then the tapestry unfurled in front of the doorway, and there it was.

Twenty feet high and ten wide.

Composed of nothing less than the finest fabrics and dyes in Equestria.

So round, so smooth and tight, so perky.

Luna’s butt.

It marked the second of only four times in recorded history that Princess Celestia has been left utterly dumbstruck.

Chronicles of the time say silence reigned for over a minute. Finally, against all odds, Grover burst out laughing. He got the joke, he claimed. He understood it. Quite a sublime joke it was, too. The audacity, for Equestria to solidify the treaty by doing something so rude and crude only friends did it to each other. It was a casual ribbing between totes besties (which they were, thanks to the success of the treaty), nothing more or less. And for Luna to keep up the joke for so long once he arrived. Of course, they probably should’ve included a letter of explanation in there as well, but still.

Yes, Celestia confirmed, that was a mistake on her part, one she should’ve caught sooner, but Grover’s explanation was absolutely the intent behind the picture in the first place (and her voice was so high-pitched it almost passed out of the audible spectrum because she was suppressing her laughter, not because she was nervous, no sir). Of course, Grover said, he’d need to use lots and lots of money to employ unicorns of his own to return the favor and celebrate the integrity of the treaty, which Celestia quickly endorsed. But he lacked unicorns that day, so to compensate, Grover simply went and literally stuck his butt in Celestia’s face.

(As a side note, that particular action became so infamous among the aristocracy that nobles who were particularly friendly with each other and particularly stupid began capping off their salutations by sticking their rumps in the air and waving their tails like flags at each other. Nowadays, rare indeed is the noble who, when greeting others, chooses to do a little shake, so to speak.)

Historians deemed it a miracle. Grover would go on to be one of Griffonstone’s more fickle and less stable kings, blindly spending his kingdom’s increasingly empty treasury on whatever grabbed his desire until his subjects overthrew him and locked him in an asylum with a ball of yarn. (To be fair, by all accounts, he was much happier that way.) The circumstances surrounding that particular visit were so precarious the slightest nudge could have destroyed pony-griffon relations and caused an avalanche of war that would decimate both kingdoms. For Grover to be swayed by that particular act, to respond in that particular way, was of astronomical improbability. It was an event that could only occur once in a blue moon.