33. [Battle of the Yesong River]
At that time, Da In-seon had pulled nearly all remaining troops back, intending to appear weak to Later Baekje.
Preparations were made to send the cannon corps downstream to the Yesong River.
"…I feel like we've brought too many troops," he said.
"Your Majesty, we cannot ignore Baekje's potential," came the reply.
"I understand, but isn't the burden of provisions too great? General Yang, how is the situation in Gaegyeong?"
The troops remaining in Gaegyeong were sufficient for now, but large forces were stationed along the border. Supporting them required the help of local nobles and Gaegyeong itself.
Gaegyeong had grown into a bustling city, even more vibrant than when Wang Ryung served as governor, receiving support from Pyeongyang, Seogyeong's Amnok province, and Namgyeong's Namhae province. It had become a significant maritime trading hub, a city worthy of promotion as a new capital. Even after being trampled by the Eight Banner Army, it had developed remarkably.
Though supplies were sufficient, supporting an army of 100,000 was somewhat risky. Even requisitioning from Silla would not fully relieve the strain.
Yang Gil, governor of Gaegyeong, had benefited from Da In-seon's favor, developing the city and supporting the current war.
Trusting Yang Gil, Da In-seon considered withdrawing all but the elite troops if the situation in Gaegyeong allowed.
"Thanks to Your Majesty's grace, the people live comfortably. What matter is a little food for the army?"
'Then it should be fine for now. But how long can it hold? If we've drawn the sword, we must cut through radishes as well. Should I unleash all 100,000 troops?'
Da In-seon considered leading his entire force to Wansanju, but crushing Gyeon Hwon, who claimed revenge for King Uija, might stir resentment.
"…No, 100,000 is excessive. Baekje might simply mobilize more troops to resist us."
He decided on a measured retreat. Even so, the main actors in the Baekje campaign were the cannon corps and the Eight Banner Army, so withdrawing the remaining forces wasn't a significant loss. It could be argued that bringing the extra troops had only wasted provisions, but it had not been without benefit.
The advantage came from Silla. Even Choi Chi-won, once strongly opposed to Goryeo, had come to appreciate Goryeo's military power, a key factor in his pragmatic shift.
There was no intention to attack Silla. Yet Silla officials following their queen realized that Goryeo could deploy major forces even to the Baekje front. This confirmed Goryeo as the dominant power in Silla and, after Tang's collapse, a new world order in the making.
Ten thousand—whose child's name was that? Even Silla at Hwangsanbeol could muster 50,000 troops nationwide. At its peak, Silla had similar capacity, so this campaign allowed Goryeo to demonstrate national strength across the Three Hans.
Pro-Goryeo officials began to rise in Silla, while even pro-Baekje ministers hesitated.
Just as Silla was beginning to integrate with Goryeo beyond the status of a protectorate, news arrived in Gaegyeong: Goryeo reconnaissance ships had spotted Baekje's front lines moving.
"Your Majesty, our scouts have confirmed that Baekje's front lines are on the move."
"Hm? As expected, then."
Everything was proceeding exactly as Da In-seon had planned.
Seeing the faintly malicious smile on his face, the commanders of the Eight Banner Army became confident of victory.
"What shall we do?"
"I will personally lead the cannon corps to the estuary. The remaining commanders of the Eight Banner Army will accompany me. Let us show Silla, or rather, our Goryeo, in all its glory."
Most Sillans now disliked Baekje. The nation had risen again as Later Baekje, continuing a history of bitter warfare with Goguryeo and Silla. Goryeo served as a reliable protector, and Baekje's provocations threatened Sillan stability.
The Silla populace and royal family already trusted and admired Goryeo. Da In-seon intended to deliver a decisive demonstration of power.
But another issue arose.
"The queen and Sul-yul-pyeong, will they accompany us?"
"Yes."
"They wish to see Your Majesty's modern army firsthand."
Though he had prepared to depart with the Eight Banner commanders, both Queen Sul-yul-pyeong and Queen Jinseong of Silla, along with Silla officials in Gaegyeong, insisted on accompanying him.
Da In-seon was already confident of victory. The enemy did not know that Goryeo's new weapons were ready, and their movements had already been detected. The Baekje army had walked straight into a tiger's jaws.
Still, this was a battlefield, not a place for queens to follow.
"This is reminiscent of Murong He of Former Yan, who brought his empress to battle…"
"Your Majesty and Murong He are entirely different. You always win; Murong He failed against Goryeo and the Khitans. Even if both bring women to the battlefield, the distinction in status is clear."
Indeed, it was historically accurate for rulers to accompany consorts into battle. Da In-seon merely needed a reason to keep both women in Gaegyeong.
"Fair enough. But a gruesome scene might unfold for them. Are you certain they can handle it?"
"Hah. After surviving what we endured in Khitan lands, this is trivial."
"Your Majesty, I merely wish to witness Goryeo's troops for the queen of Silla's sake."
Sul-yul-pyeong's claim was heartfelt. Queen Jinseong, realizing Da In-seon's unexpectedly gentle side, even tried to subtly test boundaries—strictly as an allied gesture, not romantic.
Above all, she was curious to see a young northern ruler fight on the battlefield.
For now, Da In-seon intended to impress the queens, solidifying their loyalty to Goryeo.
'If they wish to see, I shall show them. Silla needs a perfect reason to follow Goryeo now.'
Ultimately, he allowed them to accompany the army.
Pregnant Queen Sul-yul-pyeong and Queen Jinseong were escorted by the Eight Banner Army, while Da In-seon joined the cannon corps first, heading for the Yesong River.
Reconnaissance had already determined Baekje's naval approach, so they first deployed the Cheonja Cannons at the predicted landing point, checking the matchlocks and gunpowder.
Even if something went wrong, Da In-seon was confident of victory. With only the Eight Banner Army, he could annihilate the enemy before they even landed.
Da In-seon was a man who used his enemies without hesitation. He intended to both test the new weapons and impress Silla with Goryeo's might.
After completing preparations, he summoned the commander of the cannon corps.
"They will likely burn our ships. Let them be."
"Shall we really let them burn our ships?"
The commander's eyes widened. There were dozens of warships at the Yesong River, built by Wang Ryung to strengthen Gungye's navy. They were valuable assets for Goryeo as well.
But Da In-seon thought any ship unfit for mounting cannons was expendable, particularly since Choi Dong-sun had been ordered to prepare vessels capable of carrying artillery.
"These were Wang Ryung's old ships. We will have larger, grander vessels. Let them burn their way to complacency. When they land, we strike the hive."
'Defeating Baekje is simple: destroy the ships before landing. But for total annihilation, we must let them land and then crush them.'
"Understood, Your Majesty!"
"I place great trust in you, Shin Sung-gyeom," said Da In-seon.
Shin Sung-gyeom of the Eight Banner Army was assigned to the cannon corps. The reason was simple: he could shoot geese with arrows as requested during Wang Geon's hunts. Though guns and bows differ, Da In-seon chose him out of necessity.
By the time Queen Sul-yul-pyeong, Queen Jinseong, and the Silla officials arrived under escort, General Sang-gwi's Baekje fleet was entering the Yesong River, burning Goryeo's ships downstream toward Songak.
The flames were spectacular, like a massive campfire, tempting Da In-seon to pour a drink.
Of course, a king drinking mid-battle would be unwise, so he merely savored the scene.
"…Your Majesty, your ships are burning. Are you certain this is acceptable?"
"Why fret over such vessels? There are plenty at Jangsan and along the Amnok River. The Baekje soldiers are throwing a grand feast, unaware it is their own funeral. Isn't that right, Your Majesty?"
He smiled at Queen Jinseong's alarm, glancing at Sul-yul-pyeong simultaneously.
"Truly mischievous," she replied.
"You too, wishing to see our army slaughter Baekje, are mischievous."
"Where is a battlefield without blood and screams? I simply hope Your Majesty considers me," she said, caressing her swollen belly—a subtle attempt to pressure Da In-seon.
'So you don't want to see me die, and you fuss at my side. Fair enough. That's my wife.'
Past midnight, Sang-gwi's Baekje fleet, having burned all of Goryeo's ships, began their advance. Already, their arrogance was visible.
To Da In-seon, they were nothing more than prey entering a tiger's jaws.
"Hahahaha! The Goryeo scum never imagined our attack! Forward, warriors of Baekje! Strike Songak and capture Da In-seon and the queen!"
"Waaaaaaah!"
Their battle cries echoed across the Yesong River, unaware they had already entered the effective range of Goryeo's matchlock gunners.