The Traitor's Seed
Inju's lord Hong Bokwon was, at this time, preparing a lavish banquet with courtesans and food to welcome Jusuk, whose army had crushed Ugaha's forces and marched into Inju. But the invading army swiftly seized the city, and Hong Bokwon—who had been busily readying the feast—was dragged before Jusuk.
"Aigoo, what's the meaning of this? What have I done wrong?"
"Your father, Hong Daesun, betrayed the kingdom and surrendered to the Mongols. Weren't you planning the same, using Ugaha's Jurchen remnants to defect?"
Hong Bokwon had indeed intended to surrender if the Mongol army descended, but he had no plans to bow to mere rabble like Ugaha's forces—so he felt genuinely wronged.
"General, my father Hong Daesun abandoned even our family. Please, look into the circumstances and show mercy."
Hong Bokwon begged desperately for his life, but Jusuk was already carrying out Choi U's orders. With 3,000 household troops having already secured Uiju, it was a simple matter of severing Hong Bokwon's head.
"You talk a good game for someone who'd surrender the moment the Mongols arrive."
"The Mongols are coming?"
"The capital is preparing for war with the Mongols—there's no reason to spare a disloyal element like you."
Only then did Hong Bokwon realize this was truly the place of his execution. Preparing for war with the Mongols? Whether fact or mere words, his head would roll either way.
They came here determined to kill me!
He hadn't imagined his father's treason would provide such a pretext.
"Cut off Hong Bokwon and his entire clan's heads!"
Hong Bokwon let out a sigh as he watched the blade descend toward his neck, then screamed in rage.
"Goryeo... Goryeo won't last long either! The Mongols will thoroughly—"
Slash!
With that, Hong Bokwon's head fell.
Not long after, Ugaha led his army in surrender to Goryeo.
The Jin Dynasty was well aware of Goryeo's military regime. Once a mighty kingdom that had massacred the Jurchens, Goryeo had entered a decline with the rise of the military rulers, so the Jin saw no need to attack it militarily. Why strike a nation crumbling on its own? The Jin generals knew this full well, and Ugaha was no exception. But with independent action no longer viable, he invaded Goryeo—only to face a fiercer counterattack than expected. Judging that Goryeo had not yet reached its end, Ugaha sued for surrender.
"With nowhere to turn, I resorted to banditry. I once aided the Goryeo court during the Uiju rebellion—please spare my men."
It was truly a turning point in history.
News of Ugaha's army surrendering to Goryeo reached a special council in Gaegyeong.
In original history, Ugaha would disguise his troops as Mongols and invade again in 1226. But in this timeline, Goryeo's swift response forced his surrender.
The key to victory was simple. Unlike the original history's deployment of just 100 capital guards, the court had mobilized Choi U's household troops as the suppression force and sent them north. Word of the campaign against Ugaha allowed Kim Heeje to rally local armies, which intercepted Ugaha. Choi U had sent them primarily to eliminate Hong Bokwon, but Ugaha's surrender was a bonus—two birds with one stone.
Ugaha's surrender prompted a great council to deliberate this major state affair, as he was the man who had aided during the past Uiju rebellion.
"Your Excellency, Ugaha is a Jurchen general who betrayed our kingdom's grace. Execution is the proper course."
"Your Excellency, enlisting them to serve Goryeo and guard the borders could be wise."
The court split into two camps. One argued for death, citing Ugaha's betrayal and invasion. The other proposed absorbing their forces as border auxiliaries.
Either choice carried risks. Killing Ugaha would make the Jurchens enemies if Goryeo ever pushed north—a distant dream for now, but one that could lead to draining wars with the Jurchens. With the Jin fallen, there was no need to prop up the Jurchens as overlords anymore. They had shattered Goryeo's view of itself as the lord of the east, pledging loyalty before betraying to found their own dynasty. Still, the brutal campaigns against the Jurchens had worn Goryeo down—pure enmity wouldn't suffice.
What of acceptance? Could Goryeo truly trust a surrendering Jin general like Ugaha?
I had one solution in mind. I favored the latter approach. Betrayal doesn't happen when a nation is strong. Goryeo was now entering a second golden age—the Soap Era—where its soap was a luxury even the Mongols craved. Why would Ugaha betray again if Goryeo held off the Mongols? No. And Jurchens made formidable troops if kept in line. In later history, the Qing incorporated Koreans into the Eight Banners. Slowly assimilate them this way. Frame it as fighting the Mongol invasion together.
As the superintendent of the Firearms Bureau, I attended the council.
"Your Excellency, form a Jurchen Byeolcho and make Ugaha's kin Goryeo subjects."
"A Byeolcho of Jurchens?"
Why not? Goryeo was straining to expand its army. Even with the great families contributing fully, it fell short. Trade was rebuilding strength, but troops were another matter. The Two Armies and Six Garrisons had only just reached 8,000. Compared to the later Joseon, this momentum was impressive—but the Mongols demanded more.
"A brilliant stratagem. The Jurchens are inherently Goryeo's slaves. They dared found the Jin and insult us, but Your Excellency's mercy would exalt your authority."
"What says General Kim Heeje?"
The crucial voice was Kim Heeje, who had actually fought Ugaha. Choi U turned to him, newly arrived from Gaegyeong.
"Your Excellency, though Ugaha betrayed our bond, he knows the northern situation well. Why not use him to scout the north?"
Kim Heeje's words rang positive. A Jin general implied firsthand knowledge of the Mongol threat—better than anyone.
"General Kim Heeje is right."
"Using Jurchens to fill our ranks makes sense."
"Then so be it."
Choi U nodded, though unease flickered across his face at the council's decision.
Afterward, he stewed in clear displeasure. I wanted to let it slide, but knowing Kim Heeje's future involvement in a rebellion—and his death—made it impossible to ignore. An unknown might be fine, but Kim Heeje was vital against the Mongols. Plus, a rebellion plot had been crushed just this year.
"Father, why such worry?"
"I'm not sure Kim Heeje truly earned this merit."
Already fretting over him? Kim Heeje was an outstanding general, rivaling Kim Gyeongson or Kim Yunhu, excelling in both civil and military arts. A pity he'd die in treason. His record showed no rebel tendencies.
"Are you jealous?"
"Jealous? What do you mean?"
Choi U coughed awkwardly and looked away. He'd used Kim Heeje to crush Ugaha, after all—he was shrewd enough.
"It happens. As the kingdom's true power, Father, anyone eyeing authority draws suspicion. But Kim Heeje can never be your foe."
"Why think that?"
"New weapons and soap are sold in the south and Japan under the Choe name—what's one general? A vassal's merits belong to his lord. Look at Yang Gyu and Gang Gamchan. Their victories over the Khitans became whose glory? King Hyeonjong's."
"Sound logic."
Yes—Kim Heeje's feats would become his.
"If it still bothers you, assign him to the northwest frontier and prepare for the Mongol war."
"Not a bad idea."
And then—
"Your Excellency, Hong Bokwon's clan has been executed."
Jusuk had arrived amid the tension, presenting the heads to the capital. No more surrenders or offers of forty fortresses—even if war erupted.
Goryeo's worst traitor was gone.
"Give Inju to one of our loyal vassals."
"I'll select a suitable man."
"Speaking of which, have you produced the pig iron?"
Father turned to me after delegating to Jusuk.
We had, but not at cannon scale.
"We made some, but it takes considerable time."
I'd managed pig iron production, but the process was brutally complex.
"When can you make small cannons for handheld use?"
Choi U grew impatient. Mongol pressure mounted, and with Kim Heeje's northern feats, he needed results. Still, he had talents—wasted solely on clinging to power. Soap had already monopolized trade; Goryeo couldn't function without the Choe now. If he was anxious, time to leverage more support.
"Within a few months."
"Months, eh. Whatever you need, name it."
Maybe bronze was better than pig iron after all—easier to produce, despite durability and weight issues. Cannons in bronze, pig iron for matchlocks only. Initial run: 50 to 100 guns. Bronze cannons weren't ideal, but necessary. Even with matchlockmen, combat power wouldn't skyrocket—otherwise, Japan would've conquered Joseon in the Imjin War. But matchlocks would terrify Mongol cavalry, and that sufficed. Proceed gradually: small matchlock units and cannons, mixed with infantry and archers. Could we hold the first wave? Mongol invaders into Goryeo weren't weak, but inferior to those on the Chinese front. We'd catch them.
"Even as the main force, cannons will be key—but matchlocks will be limited for now."
If only we could churn out hundreds, thousands later. Paired with pikemen against Mongol horse? It'd shift things, but really? Later Joseon armies armed with matchlocks got shredded by Qing bannermen like dogs in summer heat.