When unifying the nation, foreign assistance had been obtained, but ultimately, even Tang was defeated, and a millennium-long kingdom was established.
Yet what of Silla today? Except for Seorabeol and the surrounding Gyeongsang Province, the rest of the territory belonged to Goryeo or Baekje. The kingdom had truly fallen.
The lands of the former Three Hans were once again divided into three.
In the past, there had been Tang, with its outstanding generals and kings. Now, Tang had collapsed, unable even to defend its own borders. What of the Silla king? Rather than attempting to revive a once-great kingdom, he played idly, leaving the nation to fade into obscurity.
Choi Chi-won envied the rise of Goryeo, a kingdom whose ruler was a far stronger monarch by comparison.
He even found himself wishing, if possible, to meet this young ruler of Goryeo.
Yu Geum-pil had been dispatched from Gaegyeong to garrison Daeya Fortress. Ideally, Silla would have supported the fortress, yet it was Goryeo's aid that now sustained it. Merely covering the garrison costs for Yu Geum-pil's troops strained the Silla treasury.
Naturally, Silla could not protest. Not only was Goryeo a vastly superior power, but if Goryeo were to withdraw support even briefly, Silla would collapse immediately.
Although Silla's officials were fully aware of their kingdom's decline, their main concern was at least to preserve the legacy of their long history.
Even Choi Chi-won could not argue with this. It was a time to accept reality.
With Yu Geum-pil's army stationed at Daeya Fortress, Chu Heo-jo's Baekje forces dared not approach. Eventually, Chu Heo-jo had no choice but to withdraw his troops.
Seeing the Baekje army halted by the Goryeo-Silla alliance, and extracting substantial tribute from Silla, Da In-seon clapped his hands in Shangjing with satisfaction.
"Your Majesty, though the Baekje forces have withdrawn, will they not return?"
"They will. Next time, Geon-hun may lead a larger force."
"Is that truly acceptable?"
Choi Seung-woo knew that Da In-seon deliberately provoked Baekje with repeated raids.
The method was somewhat underhanded, but it allowed Baekje's losses to accumulate, leading them to more military provocations.
In fact, thanks to Baekje's provocations, Da In-seon could replenish Goryeo's treasury through Silla.
The military provocations of Later Baekje became another opportunity for Da In-seon, leaving the Three Hans dancing to his tune.
'I didn't expect Baekje to react so boldly.'
"Baekje is nearly finished. Geon-hun may excel in war, but he lacks the capacity for governance. Anyway, have the waterworks been completed?"
"Yes. Only the final connections remain."
"Good. Then let us go to the Firearms Bureau."
Da In-seon had established the Hwatoong Dogam to develop firearms. Using the merchant Lee Jae-chun to procure sulfur and providing additional funds, he ensured the bureau had the resources needed.
Although the accumulated wealth drained rapidly, it was a small price to pay for exploiting Silla's resources. Once the firearms were completed, cost no longer mattered.
At Hwatoong Dogam, Choi Dong-sun examined models of various firearms with artisans.
To Da In-seon's amazement, Choi Dong-sun had already created models of the 승자총통 (Victory Cannon) and matchlock guns. In skill, he surpassed even Choi Mu-seon of Goryeo.
"Your Majesty, why have you come here personally? You could have sent for me."
"It's fine. Have you already created the matchlock's design?"
"Yes, Your Majesty. Thanks to the materials provided by Lee Jae-chun's trade company, production was unrestricted."
"That man… where does he get so much sulfur? Regardless, he is remarkable."
Lee Jae-chun was incredibly capable. Task him with acquiring something, and it appeared almost instantly. Had he been born in the future, there was no doubt he would have succeeded in every enterprise.
"The appearance is excellent, but what about accuracy? I hope it's not merely a well-made model."
"No, Your Majesty. Performance tests have been completed. Following your schematics and instructions, the firearms have been roughly replicated."
Even at a glance, the cannon and matchlocks appeared battle-ready.
"If this is 'rough,' then all weapons developers throughout history might as well be executed—they'd have nothing to say."
"We are honored, Your Majesty."
"Let us conduct a test."
Feeling the familiar ache in his body, Da In-seon picked up a matchlock to aim at a target.
"Your Majesty! The performance test is complete. Should Your Majesty not refrain from personally testing it?"
"How else would I know?"
Bang!
The test shot of the new Goryeo-manufactured matchlock pierced the target precisely from a distance.
"Excellent. This is usable. How far can it reach?"
'Choi Dong-sun… truly remarkable. Engineers excel in any era. With money and manpower, he produces results instantly.'
"For now, about fifty paces, but we can increase that range in time."
Fifty paces was typical for early matchlocks, and this initial model was near-perfect. Choi Dong-sun's skill was undeniable.
'Although matchlocks historically had shorter range than bows, that was only for early models. With further improvements, Choi Dong-sun will increase the range.'
"Good. The next test will be to the south. Using Baekje troops as targets will help us find improvements."
"Sometimes, Your Majesty, it is hard to tell whether you are a tyrant or a sage."
"Call it honesty. New weapons are meant for the battlefield. As the unifier of the Three Hans, where should we use them? Naturally, against Baekje."
For now, the immediate threat was Later Baekje. Silla could be unified at any time. Bloodshed might occur, but Silla was not a threat to Goryeo.
The Central Plains maintained friendly relations with Tang, and divided regional powers were minor enough that Goryeo need not intervene.
Thus, Later Baekje remained the target.
Da In-seon had previously sent spies to inflict minor wounds on Baekje, preparing for a larger campaign.
"Your Majesty intends to crush the Central Plains with new weapons?"
"Economically, yes. But the purpose is to establish deterrence. The Central Plains have historically leveraged population and vast lands to wage war against us."
"Indeed. That is why Goryeo, under the Go clan, survived."
Goguryeo's collapse had multiple causes—internal strife, repeated wars with Tang, and overextension. Population and territory were decisive, and recovery speed favored Tang. Regardless of era, population equated to power.
Now, Da In-seon had revived Goryeo. Yet if the Central Plains were ever reunified, invasion conditions could emerge. He needed a countermeasure.
"Yet we cannot simply increase our population; our capital base differs. Thus, the next strategy is to dominate with superior weapons, compelling silence. War may be necessary, but I do not conduct massacres without justification."
Da In-seon knew firsthand the massacres Mongols and Jurchens had inflicted on the Han.
While he did not particularly care about the deaths of Han, he understood the logic: permanent division to prevent reunification, forcing internal conflict. That was his ultimate goal.
'Historically, no emperor or king in these lands was ethnically Han. I will at least make Goryeo a true power in this era.'
"Understood. I will accelerate the firearms' development."
"Focus on improving and mass-producing matchlocks first, as their accuracy surpasses that of cannons."
"Very well."
Soon, Choi Dong-sun completed improved matchlocks with extended range. Remaining cannons and matchlocks were stored in arsenals. Choi Dong-sun then turned to developing naval artillery.
Following matchlock development, a dedicated artillery unit was established.
Since initial firepower was limited, the unit used a tercio-style formation with spearmen integrated, rather than linear formations. Only matchlock troops were involved in Da In-seon's version of the tercio.
'When we confront the Chinese next, this formation will be crucial.'
Though Da In-seon had limited knowledge of battlefield tactics, he anticipated that matchlock formations would be key in future campaigns.
As he sketched designs, Queen Sul-yul-pyeong appeared quietly by his side.
When he glanced at her, she leaned back subtly, as if to be noticed—classic "does this make me look different?" charm.
Da In-seon, wiping sweat from his brow, found his eyes drawn to her attire.
Sul-yul-pyeong wore clothing resembling a Manchu-style dress, form-fitting yet modest. The skirt was slightly wider, but it emphasized her curves.
"Your Majesty, what do you think of this outfit?"
"I must say… well-made."
"Your Majesty, I wish to enjoy a bit of leisure too."
"What do you mean?"
Da In-seon sensed trouble. Perhaps the queen had grown fond of luxury.
Her request was clear: "I want to design clothes. Provide support for me too, as you do for the firearms."
Refusing would surely offend her, and her talent was undeniable.
Though full modernization was impossible, Da In-seon aimed to develop the nation. He decided to leave clothing design to the queen.
'Modern-style clothing with traditional constraints… Perhaps I should enforce short hairstyles. Long topknots are stifling. The population is mixed with Malgal; resistance will be minimal.'
Having spent more time in 21st-century South Korea, Da In-seon disliked topknots. Though barbers and haircutting technology were limited, implementing short haircuts could stimulate their appearance.
"All right. Queen, you have full authority. I will provide ample support. Help advance Goryeo's clothing culture."
"Shall I design uniforms too?"
"For the artillery unit, yes."
"Consider it done."
Sul-yul-pyeong bowed gracefully and departed with her attendants, ready to execute her plans.
With royal approval, her initiatives could now proceed. Da In-seon trusted her judgment; she was no queen who would ruin the kingdom through extravagance.