"That seems a bit petty, does it not? Moreover, the Tang will be displeased with us after what happened last time," Choi Seung-woo cautioned.
"I can sacrifice my conscience entirely for the sake of my nation and people," Dae Inseon replied calmly. "Now that the Central Plains have entered the era of the Warring States, this is Goryeo's opportunity to revive its former glory. As for the Tang, I already have a plan."
At this time, China was fractured into the Five Dynasties and Ten Kingdoms period, with Tang's authority collapsing and the Central Plains fragmented. Dae Inseon had, in effect, accelerated the scramble for the imperial throne.
Historically, Zhu Wen had seized the Tang throne, prompting various regional kings and emperors to claim authority, marking the start of the Five Dynasties and Ten Kingdoms. But in this era, due to Zhu Wen's ill-fated Khitan campaign, Tang's power had already waned. Regional military governors took advantage of the chaos, sparking the early emergence of the Five Dynasties and Ten Kingdoms.
Thanks to Dae Inseon, the era began roughly a decade earlier than history would have it. Zhu Wen's plan to move the capital to Luoyang was rendered moot, and he had no means to consolidate power enough to claim the throne. Though technically not yet a formal "Five Dynasties and Ten Kingdoms," Dae Inseon's ministers simply referred to the era as such, following his lead. Dae Wihae and Choi Seung-woo regarded him almost as a prophet.
If he truly acts for the nation and its people, there is nothing he would not do. Goryeo is blessed to have such a ruler at this time.
While Dae Wihae and Choi Seung-woo were busy executing the king's directives, Osodo, a wandering figure from the fragmented Central Plains, finally returned to Goryeo.
"Your Majesty, I, Osodo, have returned in service to your command," he declared.
"Oh? The trickster has come back in one piece. Well then, how did it go?" Dae Inseon laughed, clutching his stomach at the sight.
It was strange behavior for the ruler of a nation, yet Osodo had long been accustomed to Dae Inseon's eccentricities. Even his own ragged appearance was laughable.
The tattered state of his clothes was due to Dae Inseon's instruction to recruit engineers from the Central Plains. The influx of Han refugees into Goryeo, boosting population numbers, was largely thanks to Osodo's efforts. Dae Inseon had contributed only modestly, providing minimal support through merchants.
"I've brought a few engineers, but…" Osodo hesitated.
"But?" Dae Inseon prompted.
"One of them… seems completely useless. But I've brought something else."
"What is this…? A drug? No, wait—this kind of drug I haven't seen before?"
From the folds of his tattered robes, Osodo revealed a small piece of paper containing carefully wrapped black powder. At first glance, it looked like opium, but a thought struck Dae Inseon instantly.
Wait… this isn't opium. Gunpowder! Who in their right mind invented this in this era?
Back when Dae Inseon lived as Choi In-seon, he had researched Choi Mu-seon for a school assignment. Choi Mu-seon had pioneered gunpowder and cannons, achieving victories against Japanese pirates at Jinpo. Often called the father of gunpowder in Korean history, he had also sought expertise from Chinese merchants in the south, influencing later Joseon weaponry profoundly.
No, gunpowder of this sort did exist in the Tang era for military use, just not widely. Bringing this here might actually help.
Gunpowder was known, though rarely used, even in early Goryeo. The real issue was production methods and weaponization. For Dae Inseon, arming the Goryeo army with firepower was paramount, so he welcomed the opportunity—though his initial doubts faded entirely when Osodo introduced the creator.
"The one who made this powder is named Choi Dong-soon. If you sponsor him, he promises to create things that will surely please Your Majesty."
"What? Bring him in immediately."
Choi Dong-soon? Could it be that, like me, he time-traveled into this era?
The man Osodo brought in was a young, well-dressed boy of roughly Dae Inseon's age. Despite being Chinese, his attire was stylish and reminiscent of Goryeo clothing, strangely familiar.
"You must be Choi Dong-soon?" Dae Inseon asked.
"Yes, Your Majesty," the boy replied, bowing deeply.
Though Han by birth, he spoke Goryeo perfectly and addressed Dae Inseon in proper Goryeo manner. Odd indeed.
Dae Inseon had one burning question, despite fearing it might be forbidden:
"Do you know anyone named King Chunhye or similar?"
"Who is that? A king who received loyal favor?"
Choi Dong-soon frowned, genuinely unfamiliar with King Gongmin.
…Coincidence?
The name matched, but the person clearly did not. Still, the coincidence of names and similar research seemed too precise. Perhaps, like Dae Inseon, Choi Dong-soon had somehow traveled from the future.
"You really are Tang, huh?"
"Well, technically my ancestry is Silla, but life takes unexpected turns, does it not?"
Dae Inseon grew increasingly suspicious but recognized no hostility. More importantly, Choi Dong-soon was exactly the gunpowder expert Goryeo needed.
If I hesitate, he might end up aiding Baekje or Silla, building cannons against us. I must bring him in.
"Very well. What do you wish to do?" Dae Inseon asked.
"I want to create gunpowder weapons. These are my designs," Choi Dong-soon declared, presenting detailed schematics of early cannons, ammunition, and gunpowder.
Dae Inseon felt a twinge of disappointment—he had once envisioned arming Goryeo with matchlock guns himself. Still, considering the era, the plans were exceptional.
…I have no idea how this works, but judging by his drawings and name, this isn't a fraud. Accepting him will drain the treasury, though—grain must be purchased for the Han refugees.
"Please, allow me to develop gunpowder," Choi Dong-soon begged.
"You're ambitious. Very well. See this," Dae Inseon said, revealing his own sketches of cannons and matchlocks.
Although primitive and different from modern firearms, Choi Dong-soon's astonishment was genuine. He hadn't expected Goryeo's king to think along similar lines.
"Your Majesty… you can handle gunpowder too?"
"No. I merely provide the toys; the crafting is your work."
"Then may I play with these toys?" Choi Dong-soon asked excitedly.
Dae Inseon made his decision. This boy was essential. He would be given full support to develop weapons for Goryeo, strengthening deterrence across the Central Plains.
"If you remain Goryeo's loyal subject, more ideas will follow. I'll provide the toys, sponsor your work, and exhaust your creativity until your last breath. Can you accept?"
"This continent is no place for me. I'd die before realizing my dream. I will serve Your Majesty faithfully!"
"Then name your son Choi Mu-seon," Dae Inseon added with a smirk.
If this is the real Choi Dong-soon, we must involve his son in Goryeo's gunpowder development. I'll need to stockpile sulfur.
After meeting the other engineers Osodo brought, none matched Choi Dong-soon's caliber. Dae Inseon established the Firearms Bureau, placing Choi Dong-soon in charge with master artisans from the capital under him.
Having the knowledge of state policy, Dae Inseon now only needed labor to implement it. With the Paegi army strengthening his royal authority, he resolved to pursue every feasible project.
"First, let's build a water supply system," he commanded.
Road networks were important, but clean water was essential. Ancient cities were often built near rivers. Even though the capital had grown into an international city, it couldn't compare to Rome.
Dae Inseon instructed Dae Bong-ye to recruit stonemasons and engineers.
The Chinese masons and architects among them found his proposed water system innovative. With rivers like the Songhua, Yalu, and Tumen nearby, they planned to connect them, creating irrigation channels for agriculture. The budget was enormous, so road construction would slow temporarily. The Firearms Bureau itself consumed substantial funds—now was the time to invest Balhae's resources fully.
"Your Majesty, how about this approach?" Dae Won-gyun, a royal minister in the Sinbu, suggested.
"Go on," Dae Inseon replied.
"With the influx of Han and Khitan, we could provide land to integrate them as Goryeo citizens, but first, give them work. Assign them to the water system project."
Though appointed casually as a minister, Dae Won-gyun's idea was clever. Dae Inseon immediately put it into action, recruiting labor from Han and Khitan populations nationwide. Those of exceptional physique could later join the Paegi or Han armies to be established.
The project strained the treasury, but the productivity gains would be obvious. Seen as an investment in the future, the expense was worthwhile. Securing land for mo-naegi farming was now possible with central Korea pacified. Continued exports to the Ten Kingdoms ensured a steady revenue stream.
"Hahaha! Money begets money. The Sui Emperor spent without earning—look at the Grand Canal mess he made," Dae Inseon laughed.
"Perhaps we should send envoys to the Tang? Daebong-ye expressed interest," Choi Seung-woo suggested.
Even amid massive waterworks, Dae Inseon was eager. Sending envoys would further placate the Tang, while Osodo had already used clever schemes to manipulate them.
"Hmm. Sending envoys before Tang collapses is wise. But first, we'll squeeze them a bit more. Daebong-ye is still young—only high-ranking envoys should go. Uncle, you will accompany him."
Dae Inseon appointed Dae Wihae and Dae Bong-ye as envoys to the Tang.