Chapter 27: Prince Gwanghae’s Kingship
The reign of Joseon king Seonjo saw factional struggles between different neo-Confucian schools of thoughts break out, namely the older Westerners and the younger Easterners. The factional politics culminated in the purge of 1589, where key Easterner Jeong Yeo-rip was accused of treasonous behavior against the king through his activities in a secret society he had founded and was driven into suicide, leading to a cascade of executions and exiles of any Easterners suspected of links to Yeo-rip’s supposed rebellion. However, in 1590, leading Westerner Jeong Cheol was dismissed from the government and Grand Secretary Yi Sanhae took full control, installing his new Northerner faction, a recent Easterner splinter faction, at the helm of government. He remained unchallenged as the power behind the throne for 18 years, expanding trade relations with the Japanese, particularly the Mōri and Sou clans, and aiding Ming China in 1605 against Nurhaci’s Jurchen forces at the Battle of the Suzi River.
In 1608, King Seonjo died and was succeeded by Crown Prince Gwanghae, who is referred by historians today as Gwanghae-gun during his reign. Having led the Joseon army at the Battle of the Suzi River, he witnessed firsthand the inferiority of his own country’s troops amidst the Ming-Joseon victory, Ming troops being much more proficient with gunpowder weapons and maintaining a higher level of discipline. Coupled with the reality of more powerful neighbors emerging in the form of Oda Japan and a wounded but formidable Jurchen confederation, the new king embarked upon a spree of reforms across the board to strengthen his kingdom against any future invasions. He implemented the Daedong law, initially in Gyeonggi province and later to the rest of Joseon, which established taxation based on rice rather than local commodities, easing the burden on the populace . Gwanghae-gun’s administration also reintroduced the hopae identification system [1], cultivated the publication of new books, documents, and other literary works, and maintained flourishing trade with Japan.
Portrait of Joseon king Gwanghae-gun
Gwanghae-gun focused the bulk of his time, however, on reforming the Joseon army. He built up a small but elite standing army and centralized conscription and local levy mobilization methods, with messengers from the main army now responsible for relaying the king’s orders as opposed to local troops waiting on a general with an army to essentially pick them up. The new Joseon infantry began training with arquebuses with the old seunja hand cannons falling out of use, while mounted archers and “hwacha” rocket arrow propellers continued to be important elements in the reformed military.
Gwanghae-gun’s new army was tested in 1618 when a tribal horde of 20,000 of the Holjaon Jurchens crossed the Yalu River and began raiding the northern countryside. The king sent a force of 25,000 to confront them under the generalship of Gang Hong-rip and his forces would meet the Holjaon in battle at the Battle of Gilju. In the first hour, Hong-rip’s cavalry and the Jurchen horsemen charged towards one another, exchanging volleys of arrows while also engaging in clashes of swords and lances. Hong-rip then suddenly ordered the cavalry to retreat, making it look like the battered and outnumbered Joseon mounted troops were routing when in reality they were executing a feigned retreat. The well-trained cavalry, pursued by the Jurchens, split into left and right wings at the last possible moment, opening up a gap in the center. They then retreated for slightly longer before reversing course and leading another charge against the pursuing Jurchen horsemen, while the Jurchens who galloped through the gap in the center were greeted with arquebus fire, hwacha fire arrows, and even cannon balls from 2 Ming field cannons Hong-rip had brought onto the battlefield. The Joseon infantry followed up their projectile barrage with a frontal assault, and the crippled Holjaon force shattered, the survivors barely managing to cross back across the Yalu River. Gwanghae-gun’s reformed army emerged victorious, suffering only 2,000 casualties.
Blue=Jurchen, Red=Joseon
This huge victory proved the effectiveness of Gwanghae-gun’s reforms, and they would be cemented for good. After the battle, there were fears that Nurhaci himself would lead an army into the peninsula. However, the khan of the newly declared Later Jin realm was preoccupied in a war with the Ming-backed Northern Yuan khanate and was therefore unable to exact revenge. In the meantime, Joseon’s borders were secure. Gwanghae-gun thus continued to have a free hand in government, enthusiastically backed by the ever-dominant Northerner faction [2]. Secretly, however, the conservative-minded Westerner faction, out of power for the last 30 years, were biding their time against a royal court they viewed as overly liberal and ambitious.
[1]: The hopae system, first established in 1413, mandated males 16 and older to carry identification tags bearing the individual’s name, place of birth, status, and residence.
[2]: With Yi Sanhae’s uninterrupted tenure lasting until 1609 and the strong leadership of Gwanghae-gun, the Northerner faction never splinters into Greater and Lesser factions.