Making Gunpowder in Goryeo
“Injun, who am I?”
Injun stared at me with a strange look. His expression screamed, Why ask something so obvious? That pitiful gaze, like he was looking at something pathetic, made me clear my throat awkwardly. What an insolent face to give the young lady he served.
“Miss, forget that trivial stuff—for this job, things ended up exactly as I ordered, and the soldiers are grumbling like crazy. You could've just brought Chunsim. Why drag me along too? Ugh.”
Because I'm putting you in charge of this, obviously. It's not like I can check on it every day myself, right?
“Got it. Shut up, you.”
This slave punk's gotten too cocky. Just you wait. You'll never escape slaving away under me.
Anyway, I was dead certain this cannon would work somehow.
“Alright, let's get ready.”
At my command, clapped hands signaling the start, the Byeolcho Army loaded the cannon onto the carriage and primed it just as I'd explained beforehand. Behind me stood General Park Songbi, sent by Father—half to watch me, half to guard me.
The completed cannon finally belched its shot.
Boom!
The shell flew far before slamming into the ground.
“General Park Songbi, what do you think?”
Turning with a proud grin, I found Park Songbi's jaw on the floor. What're you staring at? You're embarrassing me.
“Truly wondrous, my lady. How on earth...”
“Didn't I tell you? The mountain spirit helped.”
Whew, thank god I crammed on gunpowder beforehand. What would I have done otherwise? I'd clung to those memories in my head since birth, terrified of forgetting for a day like this.
“To produce enough for war, we absolutely can't let this leak.”
“Management has to be airtight. It's sensitive to fire.”
Properly stored in sealed containers, that is. I'd heard gunpowder factories had caught fire before. But we couldn't slack on production just because of the Powder Bureau—we needed more than that. With Father holding absolute power now, we had to build a rigorous management system.
“If managed well, this'll be a game-changer in war.”
“Call Father.”
It'd leak eventually now that it'd been developed. Better if Father oversaw it personally.
And sure enough, Choi U himself graced the test site after Park Songbi's report. Doubting at first that I'd actually made something, he mobilized the soldiers to fire the cannon—and his jaw dropped.
“What do you think? Arming with this will give us real power.”
Song was already using gunpowder; we had to match that. Gunpowder was top secret even in Yuan, stolen by Choi Musun somehow. I'd advanced it by over a century.
“You really made this yourself?”
“Of course. I'm the only one in all Goryeo who started this.”
I thrust out my chest proudly, boldly. Majestic.Your daughter has done her Choe clan proud, worthy of ruling Goryeo. A man would've looked cool, but this body was different.
“My lord, the young lady has achieved a monumental feat for our nation.”
“But making weapons like this...”
As I casually opened my mouth like it was no big deal, Choi U swallowed hard.
“Won't we need to build up our military strength?”
Gunpowder weapons → new artillery branch → military expansion → with Goryeo's situation, scaling the army means all sorts of reforms. In other words, the need for reform was now glaring.
Bury it? No way. It'd spread subtly now that I'd demoed it, and if buried, even puppet Emperor Gojong might try making his own. I'd used the forge; nothing stopped him.
Either way, Father would have to leverage this to solidify power. For Ubong Choe clan's sake. Like it or not, he'd reform the nation. At minimum, better prep against Mongol invasion than original history.
Choi U stared blankly into space, calculator whirring in his head, thinking just like me. Unless it was too costly or labor-intensive—which my niter bed method wasn't. My approach kept production cheap.
No excuse to shelve it. Monopolizing benefited Choe. But basing Choe's future on gunpowder meant military reform, agricultural reform, all reforms. Father already had sycophants; he'd purge the hated ones to appoint gunpowder managers. Time for a shake-up.
“Heavens preserve us.”
Choi U collapsed, overwhelmed by the joyful tasks ahead. Scolding me for making it? It'd aid war; monopolized, it'd steel Choe regime. His cronies might yap, but they'd see Choe grow stronger.
“Indeed. The mountain spirit must see our Choe clan—and Goryeo—as its guardians.”
Rationalizing at last, Choi U gently stroked my hair. Fatherly love, sure. But the future looked daunting.
“You're truly remarkable. Thanks to you, Ubong Choe's glory will last a millennium.”
Okay, think. To expand military: boost birth rates first? For that, agricultural reform. A military regime with only Byeolcho as regulars? Absurd. Even post-rebellion, it wasn't nation-shattering. Scale up now, and we could build massive forces.
But big armies need birth rates to sustain. Choe regime now bore heavy tasks. No dodging it.
Choi U faced sleepless nights in the Defense Command; I visited often, excusing it as helping my burdened father.
“The Second Army's Six Divisions, once over 40,000, are just shells now.”
Choi U despaired at the reality. New weapons meant new branches, natural growth—but originals were wiped.
Self-inflicted by militarists absorbing armies to hold power.
“Essentially merged into Defense Command's Byeolcho. But even Byeolcho falls short of Second Army scale.”
“We need tens of thousands at least. Why this mess? Urge local clans for household registers. They must have private troops.”
Defense Command echoed with Choi U's wails today too. Fair point. Goryeo rose with clan aid. Even Taejo Wang Geon was Goguryeo clan. Goryeo mobilized more than Joseon—170,000 expeditions, 300,000 at Tongju (rabble, but still).
How, with less population? Decentralized, clan-based. Local functionaries from clans paid taxes up, ignored central. Clans raised private guards.
Risky—rebellions crippled war effort in Yeo-Mong wars. Hard to unify command. But overcome, mobilization beat centralization. Local autonomy meant quick response, no golden time lost. Superior to Joseon.
Drawbacks, yes—but fix them, and total war possible.
“Yes, my lord. That should muster at least 100,000.”
“No choice. Rebuild Second Army Six Divisions, even smaller. Half of 40,000 at least.”
“But that'll cost a fortune.”
Choi U's eyes flicked to me, How'd I end up with this daughter?
Toss-up anyway. Decades of island defense? Goryeo doomed. Sure, Yuan's son-in-law perks existed—but better than crown prince wanking to Mongol recognition later. Territory wrecked, yet proud? Nah.
Block Mongols to save Hwangnyongsa's nine-story pagoda, sovereignty intact.
“Defense Command foots it.”
Choi U raised the military anchor. Wrinkles spread; hated bleeding wealth.
After declaring buildup, alone, he ventured cautiously.
“Daughter. Beyond that cannon, other weapons?”
“Plenty possible, Father. But...”
I knew gunpowder arms. With forges, hand cannons or matchlocks feasible. Needed cast iron though—help required.
“But?”
“This wrought-iron barrel lacks durability for rapid fire. Mass-produce, sure—but sturdier's better, right?”
Wrought-iron cannons: productive, but fragile.
“Solution? This alone seems decades—or century—ahead.”
Nope. Song used gunpowder arms already. Purity questionable.
“Need cast iron production. Unsure how much with Goryeo's tech.”
Joseon barely trickled it. Goryeo could with my knowledge experimentally. But quantity key.
“Fund it, and you'll produce?”
“Yes. But massive funding.”
Doable. Imports workaround, like sulfur. Short? Mix steel with wrought barrels.
“I'll appoint you Byeolgam of the Bureau of Firearms. Not yet—but it'll leak soon. Prepare.”
Bureau of Firearms Byeolgam. Militarist version of Hwacheong Dogam, probably.