The Reliquary of the Heroes
Luna opened her eyes and looked around. Her vision darkened with each heartbeat. Her eyes watered. The air smelled... different. Danker. Low sun streamed in the windows, nearly blinding.
She forced her eyes to focus, and the first thing she saw was a rainbow-maned pegasus...
...wearing the Element of Loyalty.
A white shape loomed over her, and then knelt down. "It has been a thousand years since I have seen you like this," said the shape. "Time to put our differences behind us. We were meant to rule together, little sister."
Luna looked up. Her vision cleared and she recognized Celestia.
The others in the stone chamber exclaimed something. Luna's blood pounded behind her eardrums, she couldn't understand the words. Her guts cramped, her balance lurched, and she fought the urge to vomit.
Only a few moments ago, in the throne room, Celestia had been yelling at her to lower the moon, Luna felt darkness swirling, what happened oh gods what did she do the beast was taking her taking her mind and her body what horror had befallen...
"Will you accept my friendship?" said Celestia.
There was more noise from the other ponies, but Luna ignored it. She felt a void open up, blacker than the dark side of the moon, and readied to strike. So close, the spell would have killed even Celestia.
She aimed, prepared to light her horn, and...
And...
She bit her tongue and tasted blood. Her heart slowed. Her rage died.
Luna lurched to her hooves and leaned into Celestia. "I'm so sorry! I missed you so much, big sister!"
"I've missed you, too."
They left the castle ruins and the forest, and reached a town. The six Bearers went separate ways to prepare the party.
Luna lifted her wings to let her sweat dry in the breeze. Royal Guards provided a ring of privacy around the two princesses, standing in the center of the town square.
Luna blinked in the sunlight and cocked her head. "Sister.... this town was not here yesterday."
"It was."
"Sister, I am missing an important detail of some variety. The beast... she took my mind... and then my consciousness submerged, like falling into the ocean, tied to a boulder. What happened that I do not remember?"
"The elements banished Nightmare Moon."
Luna felt her knees weaken and she flopped down on the dirt of town square. "That was my name?"
"She... you... were banished for one thousand years. One thousand years to the day, as near as I can judge."
Celestia kept talking. Luna's vision went dark, tunneling down to pinpricks as she stared at the clock on the town hall's spire. The second hand ticked, ticked, ticked.
One thousand years!
Luna heard only rushing blood, Celestia's words gibberish.
"Sister!" Luna interrupted.
"Yes?"
Ponies stared at Luna. Foals covered their ears. A glass window in the nearest shop crazed.
"Sister," Luna whispered. "What happened to my daughters?"
"Luna," Celestia said, "we must stage-manage your return to society perfectly. For one thousand years, you have been the bogymare parents scare their foals with. Pretend to enjoy this party, and tonight, in my private chambers, I will tell you everything you wish to know. I will answer any question, no matter how.... For now, you will play the role of 'happy princess.' Understood?"
"Are my daughters dead?"
"My sister... you know I will never lie to you. So before you ask me questions, think: 'do I really want the answers?'"
"Are my daughters dead? My husband?"
"Yes, for almost one thousand years."
"I... but... but... but not ten hours ago... I ate breakfast with them."
"Dissolve the Lunar Battalion," Celestia ordered, pointing a hoof at some of the papers. "Spread the troopers across the rest of the guard. Give the officers honorable discharges. ...and then keep an eye on them."
The Chancellor nodded, and scratched a note with a quill held in his flight feathers.
Celestia sat in her office, huddled with her Chancellor, with her Prime Minister, and with the palace majordomo. Papers shuffled. Celestia would be years coping professionally with the loss of Luna.
And centuries coping with it emotionally.
She closed her eyes and took a few deep breaths. Had it really only been a few hours ago? Was her sister really gone?
The door slammed open, and four guards stormed in, surrounding a young unicorn mare in the gold uniform tunic of an officer-cadet.
Dark blue-purple, with a white mane and tail, her cutie mark was a shield in front of a stone castle curtain-wall.
The cadet was the tallest unicorn in Equestria.
...even taller than her mother. Celestia felt a catch in her breath.
The young mare snapped to attention and glared at Celestia. Her left ear spasmed. The four guards stood close to her, nostrils flared, eyes narrowed.
The unicorn cadet wore a scabbard across her withers, and the guards kept glancing at the sword's hilt.
Celestia stood up and bowed. "Princess Tranquility."
"Your highness," Tranquility said, failing to return the bow, "take my sword and take my head and be done with it. Quickly, before my courage is depleted."
Tranquility levitated her scabbard free and slid it across the desk, scattering the papers of state.
"You're no criminal," Celestia said.
The young princess threw herself flat to the marble floor and arched her back to expose her neck. "Aunt, I shall not resist, but be quick and show me the mercy you did not show my mother. Kill me before my sense of honor fades and I follow my dam into ignominy and treason."
Celestia looked at the others in the room. A tremble ran down her leg, and her wings twitched, still sore from the battle. For a split second, she saw the infant she had once rocked, and not the teenager in front of her.
"Should we go, your highness?" asked the Prime Minister.
"No," said Celestia. "Stand witness to this moment. Stand witness in the stead of all of the Crown's subjects."
Tranquility sobbed once, shaking, but didn't move. Her neck awaited the blow, muscles tense.
Celestia levitated up the scabbarded sword. "Have you committed treason, niece?"
"My honor is tainted. I will not live in dishonor."
"Do you intend to commit treason?"
"My blood is putrid with mother's treason."
"In your seventeen years of life, have you even once seen the Crown punish a foal for the sins of the parent?"
"Kill me before I lose my nerve, aunt."
"Answer my question! Even once, has the Crown revenged itself on the foals of the criminal?"
Tranquility shook harder. "No, your highness."
"Arise and stand at ease, beloved niece."
Tranquility stood, her knees quivering, her breathing fast.
Celestia looked at her niece, and her eyes stung. She swallowed twice before she could speak. "Do you acknowledge your mother committed the highest of treasons?"
"Aunt, the blood in my veins is attainted. Spill it all, on this marble before these witnesses, before it corrupts my honor. I am the spawn of treason. I am a weed in the garden of state. Uproot me and burn me."
"Where is your sister?" Celestia asked. "Do you wish me to kill her, too?"
Tranquility's dark face paled. "No! She bawled herself to sleep, and her nanny put her to bed."
"Her blood is your own," Celestia said. "By your logic, Equinox must die, too."
"My sister is but six, aunt. She is innocent."
"You are innocent of any crime of your mother's."
"Aunt... I am dishonored. Look at the guards." Tranquility gestured to the four troopers surrounding her. "See the hatred in their eyes. I shall be suspect for every day of my life."
"You have committed no crime, Princess Tranquility," Celestia said.
Tranquility's aura ripped the diamond insignia of a first-year cadet off the collar of her uniform, and threw it on the floor. She stomped on it, her hoof grinding it against the marble.
"How can I serve? How can I expect troopers to follow my orders when they will all suspect me of a ruse or stratagem to betray the realm and revenge myself upon you?"
Celestia allowed herself a smile. "Plan you such machinations?"
"No! But look at my cutie mark! Shield and wall. I was born to be a Princess of the Sword, but how shall I serve when nopony will trust me to command?"
"What makes you think nopony will trust you? What makes you think no trooper will follow you into battle?"
Tranquility's voice cracked. "Because I am the eldest and beloved daughter of the greatest traitor in history."
Celestia dropped the scabbard back to the table, and walked to her niece, and nuzzled her.
Tranquility gasped, and hugged Celestia around her barrel. Her body shook, and Celestia hugged her back, squeezing her hard.
"I will not lie to you. You will face unique challenges," Celestia said. "You will need to work twice as hard to prove yourself half as loyal. But I shall need you, alive and obedient. My son is but an infant, and your sister a foal. You are now the second-eldest of the Royal Family."
"By the heavens..." Tranquility said, "I'm first in line now! Aunt, you must kill me where I stand. If something should happen to you, the suspicions against me will tear the realm apart."
Celestia bit her lip. "A complication, indeed. I proclaim my son Crown Prince, Princess Tranquility second in line, and Princess Equinox third. Is your objection slaked?"
"Kill me, aunt, or I will do it myself!"
"We forbid it," Celestia intoned in the Royal Canterlot Voice. "The Crown commands you: you shall not kill yourself. We shall not kill you." Her voice returned to normal. "I love you. I have lost my sister, I cannot lose you, too. How would we explain suicide to your little sister? So soon after she lost her mother?"
Tranquility finally broke, tears streaming, body spasming as she sobbed. "Aunt... auntie Tia... what will I do?"
Celestia hugged the young mare, pulled her close. "You will be my beloved niece. You will be a Princess of the Blood. You will serve as an officer of the Guard. You will help me raise your sister. You will be like my daughter."
Tranquility buried her face into Celestia's withers. Despite her uniform, her regal bearing, her towering size... Tranquility was still a foal, only on the cusp of marehood. Only her royal blood had opened the doors of the Academy to one her age.
Tranquility bawled. She pounded her hooves against Celestia's ribs. Celestia felt the wetness of Tranquility's tears soaking her withers.
Celestia looked at the guards, the majordomo, the chancellor, and the Prime Minister. She nodded slightly.
After some time, as Tranquility's sobs slowed, Celestia took a step back, pulled herself to her towering height, and looked down on her niece.
"Prince-consort Astur took to his hooves," Celestia said. "I doubt we shall see him again. I name you your sister's legal guardian."
Tranquility sniffed. "Father never was worth much. Mother erred in loving him."
"I know you well, Tranquility. You have a deep sense of honor, and a reverence for the symbols of your profession." Celestia gestured to the uniform Tranquility wore.
Her niece sniffed, wiped snot onto her uniform sleeve, and nodded up at her aunt.
Celestia levitated a dagger from one of the guard's belts.
"In front of me, yourself, and these witnesses, swear a blood oath of fealty to the Crown and the Realm. I will trust you, of all ponies, to keep such an oath."
The younger princess nodded, and levitated the dagger up, and—whack-whack—cut off the top three-quarters of each of her own ears.
She slammed the dagger point-first into the polished wood of Celestia's desk, and let the severed ears fall to the white marble of the floor.
Blood streamed down the sides of her head, into her eyes, staining her gold uniform around its collar, and dripped to the floor.
She snapped to attention, grimacing against the pain, but silent and still.
Celestia stared into the foal's eyes for several seconds, then nodded.
Tranquility genuflected, chest flat into the growing pool of her own blood. "To last last drop of blood in my body, to the last beat of my heart, to the last breath of my lungs, I swear to serve the Crown and the Realm, if you will but accept my fealty."
Celestia leaned down and nuzzled her niece, smearing blood across her own white cheeks.
"Arise, beloved and trusted vassal. Beloved and trusted niece. Beloved and trusted daughter."
Tranquility stood, blood still flowing freely, and stared into Celestia's eyes. "My only wish for my life is to die in your service, my liege."
"Get to the healers before you bleed to death. Dying here will not serve the realm. I would have accepted one drop of blood from a pricked foreleg, you impulsive ninny! You have maimed yourself."
"I will remember my oath every time I look in a mirror."
"You will explain to your sister that I do not expect the same blood oath from her."
"Yes, my liege."
"I forsee dark days ahead of us, Tranquility. You shall have many opportunities to die in my service."
The young princess frowned, then nodded her head. "Good."
Celestia trailed off, and took a sip of water, her throat thick from remembered tears a thousand years old. "Her urge to suicide passed, and she returned to the Academy the next day, her ears bandaged. I made sure her instructors watched her closely for signs of danger to herself... or to others."
"Please..." Luna said. "Please, tell me Tranquility did not fall into ruin as well..."
They sat on overstuffed chairs in Celestia's chambers, near the fireplace. It blazed and crackled, but a shimmering spell kept the heat out of the already-warm room.
Celestia moved to Luna's chair, and sat down next to her, flank-to-flank, and wrapped a wing over her. Luna leaned in to her sister, savoring the warmth, for Luna was shivering, suddenly.
"Luna... your daughters are both dead. They did not ascend, and remained unicorns, mortal. Their bones are hundreds of years dust."
"What happened to Tranquility?" Luna asked. "Was she a traitor like me, or a servant of the realm?"
Celestia said, "Her crypt is in the Canterlot sculpture gardens. Her likeness was the first sculpture. We do not honor traitors so. Only heroes."
"Take me."
Celestia unwrapped her wing from Luna's back, stood, and took a step toward the door.
"We... I cannot wait, sister, for the walk. Help me teleport."
Celestia placed a hoof on Luna's withers, and—
SNAP!
—they were under the moon and stars, among the stone likenesses of legends and myths. Luna swooned, still recovering from her magical ordeal that morning. She shook her head and regained her balance.
Both alicorns lit their horns, illuminating the darkness.
Celestia waved a hoof. "This is the oldest, and most hallowed, section of the Gardens: the Reliquary of the Heroes. Both of your daughters, and dozens of your descendants, repose here."
"Descendants....?"
Luna looked around, and saw an obsidian plinth, polished into a black mirror, supporting two marble sculptures. The first statue was a tall unicorn, standing, head raised and glaring down an aristocratic muzzle. The face and body were criss-crossed with scars, the ears cropped.
The second statue was the same unicorn, fallen on her back, legs splayed, one foreleg bent impossibly, shattered bone sticking through the skin, ribs cleaved open across her flank, one eye glazed in agony, the other eye a ruined mess. Even in the monochromatic grayish-white marble, the wounds and flowing blood were obvious.
The excruciation of the scene polluted the very air, the artist's brilliance still evident hundreds of years later.
Luna sucked in breath. "My foal... my baby... what happened after I abandoned you?"
In carved six-inch letters, the plinth proclaimed:
HERE RESTS
HER INDOMITABLE HIGHNESS
PRINCESS TRANQUILITY OF THE SWORD
FIRST HERO OF EQUESTRIA
SHE HELD THE BRIDGE
9th month, 12th day, 97th year
Luna sat, raised her head to the sky, and keened. Lighting crashed and thunder rumbled.
Dizziness swirled around her and, for a moment, Nightmare Moon tickled at the base of her spine, scrabbling for re-admittance.
"The date..." Luna gasped. "The date of her death... my daughter died at twenty-one!"
"Yes," Celestia said. "She had so much to prove. To herself, to others. She ended one hundred and nine lives in battle. The Guard's yearly trophy to the best swordspony is still named for her. Tranquility sought death, at every opportunity, to prove her loyalty to herself, and to everypony else. Eventually, she succeeded."
"How—why—what happened?"
"The greatest epic of Middle Ponish poetry is entitled, 'Tranquility at the Bridge.' It is the first lay of the Lays of Ancient Pone. It is taught in schools to this day. Lord Macintosh Hills' masterpiece."
"Sister," Luna said. "What happened to my daughters?"
"They died, Luna. They died in blazing glory, as heroes of Equestria."
"Equinox died in battle, too? To me... to me... in my yesterday, she was a filly who could not sleep... unless... unless I gave her precisely nine kisses goodnight. And... and... you tell me she died on the point of a sword?"
Celestia shook her head. "Tranquility was a hero of the sword, Equinox died fighting plague. Equinox was the greatest healer of her generation. Her glory shines no less brightly because she, too, laid down her life to save others."
Luna collapsed to the grass and curled around on herself, her hornlight dying, the dew wetting her coat. "Tell me the stories. I must know!"
Celestia lit her horn brighter, and shifted her head to change the angle of the light.
Luna saw fine writing on the obsidian plinth, a poem of seventy stanzas.
"An epic... my daughter's epitaph is an epic poem, taught to schoolfoals... sister, my heart tears in two. Nopony writes an epic about an easy or painless death."
"I held her, at her end, cast a spell to take her pain onto myself, and whispered my love into her ears as she faded. The second statue is, I am sorry to say, accurate. The sculptor wanted to portray me cradling her, but I forbade it. My... my coat was stained red for weeks. Tranquility's death was terrible, but she spilled her lifeblood to save Equestria. You raised the greatest hero of her century."
Luna clenched her eyes.
Celestia said, "Let me read you the middle stanzas. Every schoolfoal in Equestria memorizes this excerpt in the fifth grade." She stepped closer to the engraved stone and brightened her horn. She read:
"But Celestia's brow was sad,
And Celestia's speech was low,
And darkly looked she at the wall,
And darkly at the foe;
'Their van will be upon us
Before the bridge goes down;
And if they once may win the bridge,
What hope to save the town?'
"Then out spake brave Tranquility,
The Captain of the gate:
'To every mare born to this realm
Death cometh soon or late.
And how can mare die better
Than facing fearful odds
For the ashes of her sires,
And the temples of her gods,
"'And for the tender mother
Who dandled her to rest,
And for the daughter who nurses
Grandfoal at her breast,
And for the holy maidens
Who feed the eternal flame,—
To save them from false Sextus
That wrought the deed of shame?
"'Haul down the bridge, my Aunt,
With all the speed ye may;
I, with two more to help me,
Will hold the foe in play.
In yon strait path a thousand
May well be stopped by three.
Who of our land will with me stand,
And keep the bridge with me?'
"Then out spake Spurious Larhorsius;
A pegasus proud was he:
'Lo, I will hark to thy right Mark,
And keep the bridge with thee.'
And out spake strong Hereford;
Of earth-pony blood was she:
'I will abide on thy left side,
And keep the bridge with thee.'
"'Tranquility,' quoth Celestia,
'As thou sayest, so let it be.'
And straight against that great array
Galloped the dauntless Three.
For Ponies in their quarrel
Spared neither land nor gold,
Nor son nor wife, nor limb nor life,
In the brave days of old.”
"Is... is that true?" Luna said.
"Dark Clouds was there, commanding the engineering detachment. I raised him first Baron Macintosh Hills that very evening, for supreme valor. He penned Tranquility's epic while recovering from his wounds. Macintosh Hills recounts the events accurately, but takes liberties with dialogue for the sake of rhyme."
Luna looked up at her.
Celestia's voice weakened. Her tears glistened in the hornlight. "I... I created seventeen noble houses on that blood-soaked field. So much valor, so much sacrifice... so much death."
"Sister.... Celestia... please hold your horn steady that I may read of my daughter's death. If thou interrupt me... I cannot vouch for my actions."
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9607163
I'm working feverishly!!!
Thanks!
Not bad, really dark but cool story so far! Oh...my, nice poem at the end!
I didn't know there were any public domain ones, great inclusion!
"Luna opened her eyes and looked around. Her vision darkened with each heartbeat. Her eyes watered.
The others in the stone chamber exclaimed something. Luna's blood pounded behind her eardrums, she couldn't understand the words. Her guts cramped, her balance lurched, and she fought the urge to vomit.
Luna felt darkness swirling, what happened oh gods what did she do the beast was taking her taking her mind and her body what horror had befallen...
There was more noise from the other ponies, but Luna ignored it. She felt a void open up, blacker than the dark side of the moon, and readied to strike. So close, the spell would have killed even Celestia.
She bit her tongue and tasted blood. Her heart slowed. Her rage died."
Oh, man...a few paragraphs in, and this already sounds like a grimdark, lol. O_O Oh, boi, we're in for a rough ride! XD
'Celestia's voice weakened. Her tears glistened in the hornlight. "I... I created seventeen noble houses on that blood-soaked field. So much valor, so much sacrifice... so much death."' Oh, boy...this about to get dark, boys! (I knew this would be, but I did not know what I was diving into, lol.)
9607174
Thanks!
You might enjoy the original Lay, linked in the author's note.
Beautifully written.
9607276
Thanks! I shall do my best to keep it up.
You may have a very new account, dear author, but you are quickly becoming one of my favourite writers.
Bravo.
9607317
Thanks! I appreciate it.
Upvoted and tracked, then I read most of your other stories. You have talent! following and looking forward to more of your stories.
B.D.
9607425
Thank you! Much appreciated.
That poem left me in tears.
9607493
Thanks!
(I admit I just ponified a real poem.)
my heart!!!!!!!
9607697
9607711
please continue!!!!!!!!!!!!!!!!!
9607714
I'm working on it, hopefully Tranquility's chapter will drop in May and Equinox's in June.
9607715
yay!
Are we going to find out what happened to her other ear in the story, or is just a piece of the background?
9607984
I meant to imply she cut both off....
I'll see if I can rephrase to make it more clear.
Thanks!
9608061
So she did. I guess I misread it. Thought it had only been one.
9608083
No probs! Thanks for reading.
I saw the title and was interested then I saw the tags and though this is going to have some feels, I was right,
This hit the feels, especially after just seeing Endgame.
Serve Celestia? "Crown and Realm" appears to sound... vague in this context.
You! Shall not! PASS!!!
Wow as soon as I was reading Tranquility's Epic I had tears streaming down my face.
I believe that The Noble House of Armor is a descendant of Tranquility seeing as most of there member's become royal guards or captains of the guard.
9608710
For a second I suspected a different more blue fate. But then I realised that with how Celestia didn't argue too much against tranquility's description of her father, I wonder if he had more children after that
media.giphy.com/media/ziLadIVnOGCKk/giphy.gif
9608637
No spoilers!! But thanks for reading!
9608527
9608801
Thanks!
9608700
Being a professor of literature, Tolkien no doubt was familiar with the original story. Thanks!
Alright, you snared me in your web, now feed on me spider while distracting me with the rest of this tale.
9608806
Don't worry, no spoilers.
How in the Hell, have I not seen a story like this before!? With this setting of explaining the what if, Luna had daughters before turning into nightmare moon. If there has been, then I've missed it and I'm basically holding my breath to see how this story continues.
You'll have to forgive me SockPuppet because I have put you on an unusually high pedestal for this story. I really do hope this story will continue and continue with the quality it has started with. But alas this is not my story and certainly do not plan on asking for anything (even if I have implied such a thing).
So here's to the hope that SockPuppet enjoys writing, enjoys writing about Luna's Daughters and is not too busy living his life to the fullest to spend a minute here or there to do some loved writing.
This was powerful. I'm tearing up a little from the emotional impact. This is not an idea I've seen before, as far as I know, and you executed it beautifully. You really captured Luna's grief, while also doing her daughters proud. Particularly, the line
really punched me in the gut. It's a great exploration of how hard it is to have someone you care for do great things at their own personal cost.
9609133
9609286
Thanks to all! I'm working hard on the remaining chapters.
Jesus, man, I know that historically the way nobility honor their dead could be a bit morbid, but this is just awful. It makes me worry about the sculptor's state of mind.
9609471
Well, Tranquillity died in Celestia's hooves. She probably would have sent the sculptor to Tartarus for inaccuracy.
9609479
O, y'know, they could've just stuck with the first statue and not depict her being horribly mangled at all.
I'm not actually criticizing your story, just something in-universe that jumped out at me.
9609481
Oh, I understand it was an in-universe comment.
My thinking (which didn't get on the page) is that Celestia is playing the long game, and deliberately building a hagiography for the new nation.
So, wait...does Luna have any living descendants now?
Since she had "dozens of descendants" in addition to her two daughters, statistically some of those dozens should have living descendants now, but at this rate I'm expecting some more tragedy.
(And if she does have living scions, there's no guarantee that they'll want anything to do with her, assuming they know much of their family history...)
9609490
With Luna's lineage, no less. It should make her integration easier, to have her brood as the heroes of every foalhood.
It must still hurt like
.
I wonder, who are her closest living descendants? Has her lineage disappeared or did they spread so much as to make the whole of equestria the fruit of her own loins? Questions, questions.
9609837
9609814
I have answers to these questions but they might slow down the narrative. If they don't get into the narrative after the final chapter, I'll write a blog post.
Eh...I prefer this answer to what happened to Luna's Daughters, if they really are the stone sculptures in the Canterlot Gardens...
This way, Luna's daughter's are technically still alive, she can learn that Celestia did HORRIBLE things to them 1000 years ago, AND she has a totally legit reason to go Nightmare Moon again!
9610042
Hahahha!
No, I'm playing this one straight but you should write that!
Poor Luna. I hope she'll be okay.
What if one of Luna’s descendants was Twilight?
9608700
Swearing service to "the Crown and Realm" instead of to the current mon- ruler makes a lot of sense, especially in that moment, as rulers come and rulers go, but the Crown and the Realm Endures.
Besides, an oath made to Celestia wouldn't mean much if a few years down the line, the head underneath the crown changes, either by abdication or decapitation or simply vacation.
9610938
Umm, and who exactly speaks for "Crown and Realm"? Quite important question just hours after very close coup attempt.
It's surely a good idea to kinda speak on behalf of something bigger (like "god" or "realm") for a leader when giving orders. Not so much when demanding loyalty.
It means quite much to Celestia (who else?). If so happens, new ruler would demand new oath to him/her personally, of course, --- that's no modern democracy.
9610966
Barring the Fausticorn being made canonicical or somepony invoking the name of the Creator Deity, Celestia and Luna are pretty much gods. Swearing an oath by the gods of that setting would be like the Japanese Imperial Family invoking their ancestors, in that EVERYONE knows who they are really invoking, but have some fig-leaf of deniability.
I took the "Oath to Crown and Realm" thing as more Celestia covering her bases if she discovers that she can't run both the Solar and Lunar Courts. As we've seen in the show, by the time of Luna's Return, Celestia is generally very hooves off and only really interceding if directly asked or if there is a situation that requires that level of arcane might.
9610573
What about Cadance? This could be the reason that she always calls Celestia Auntie.
9610573
My own headcanon is that the Sparkle family are Luna's direct decedents.
Stirring opening for some epic worldbuilding. Perhaps Blueblood? takes after Astur. Where did you come up with that name?