Chapter 59: Gwanghaegun’s War Against the Jurchens
Throughout his 31 year reign, King Gwanghaegun fundamentally reformed and modernized his formerly ultraconservative and isolationist realm. The power of the neo-Confucian bureaucracy was rolled back, with its factional infighting sufficiently suppressed, and relations with the outside world enabled advancements in military technology. He also served as a loyal tributary to the Ming Emperor, joining the latter against Nurhaci and maintaining good diplomatic relations with Beijing, while also effectively defending his realm against Jurchen invasions. His successful reign would be bookended by one last task: conquest. Witnessing the fracturing of the Jin Khanate, he saw an opportunity to invade and exact revenge for the Jurchens’ previous destructive campaigns of the countryside of northern Joseon. Gwanghaegun began to prepare for war.
At this stage, the Jin khanate was still in a state of civil war, with Abkai struggling to eliminate Amin and the remaining rebels. Amin by now had elevated the late Ajige’s firstborn son, Hedu, as the main pretender against Abkai, as Ajige’s younger brothers Dorgon and Dodo remained neutral in the conflict. The rebellion finally ended in 1632, with the death of Amin at the Battle of Ula and the subsequent executions of all captured rebel leaders and the 14 year old Hedu. However, the civil war had ruptured the tight Jurchen unity Nurhaci had first forged through strength and might, and Abkai became preoccupied with keeping his realm together and calming tribal tensions. He also dealt with an invasion by Ligdan Khan in 1634, whose realm had recovered from years of warfare and had finally stamped out disloyalty among the various Mongol tumens. However, the khan would succumb to smallpox during his campaign and his son and successor Ejei would sign a truce with Abkai while he set out to exert his authority among the tumens. Although the Mongol invasion proved to be brief and unsuccessful, it took away further resources from the Jin khanate’s much-needed recovery from the civil war. These events would set the stage for the 2nd Jin-Joseon War of 1636, as a watchful Gwanghaegun slowly built up military strength until he was ready to wage war on the destructive horsemen. Joining his army was Amin’s son Hongketai, who had fled to Hanseong after the Battle of Ula and commanded a small number of renegade Jurchen cavalry ready to exact revenge for Amin’s death.
At the outbreak of spring in 1636, King Gwanghaegun left Hanseong at the head of an army of 50,000, with the crown prince Yi Ji [1] staying behind to hold down the fort in his father’s absence. His objective was to expand the borders of Joseon beyond the Yalu River and create a greater buffer between the peninsula and the Jin. News of Gwanghaegun’s advance quickly reached the ears of the Jin khan, who mustered up his Eight Banners and marched towards Ningguta where the Joseon army had marched towards, not far from the homeland of the Yehe Jurchens, the Jurchen conglomerate most recently subdued by the Jin shortly after the death of Nurhaci. The Yehe would be mobilized by Abkai, although their loyalties were not solid. Abkai also ordered several smaller forces to attack vulnerable points along the peninsular border, although these secondary assaults and raids were completely rebuffed by the border garrisons and a detachment from the main Joseon army consisting of both Jurchen allies and elite Joseon cavalry led by Im Gyeong-eop. This diversion of forces, however, would mean that Gwanghaegun’s army would be outnumbered by Abkai’s main force. However, the Joseon army was equipped with greater numbers and higher qualities of gunpowder weapons and was more unified in spirit compared to the less cohesive Jurchens.
Depiction of a Joseon musketeer from the early 17th century
At Ningguta, Gwanghaegun arrayed the army in the standard formation of the infantry in the center and cavalry in the wings, with a cavalry reserve in the rear. Placed on the right wing were the Jurchen cavalry led by Hongketai while elite, more heavily armored Joseon cavalrymen made up the left wing led by Shin Gyeong-won, with the king himself in the back with the reserves. The frontlines of the infantry was entirely composed of musketeers, followed by a line of hwachas and a block of heavily-armored swordsmen. Between the infantry center and the reserve cavalry were several cannons. The Jin army, meanwhile, was completely fronted by cavalry with a mixture of swordsmen and arquebusiers making up the back ranks. However, Abkai’s army carried no cannons. Abatai, an older brother of Abkai, and Dorgon acted as Abkai’s deputy commanders.
The battle started around at noon, with the cavalry on the wings exchanging blows first. The fighting between the Joseon right and the Jin left was noted for its ferocity stemming from rivalries from the Jurchen civil war, although the Jin’s numerical superiority gave them the edge and slowly pushed Hongketai’s men back. In contrast, the native cavalry on the left held their ground much better, and that front remained at a standstill. Meanwhile, Jurchen horse archers engaged with the Joseon musketeers in the center, riding back and forth to avoid the volleys of musket fire. Gwanghaegun held back the hwachas, cannons, and swordsmen a bit longer, although he sent part of the reserve cavalry to support his Jurchen allies. Then, he signaled for the rest of the reserve cavalry to gallop through the gaps towards the Jin center and charge briefly before retreating. The Jin fell for this unexpected feigned retreat, and this is when the Joseon musketeers and hwachas completely unloaded, delivering a heavy blow to Abkai’s men. At the same time, in an arrangement planned in advance, the Yehe Jurchens retreated from the battlefield and betrayed their Aisin Gioro overlord. In a desperate attempt to salvage any victory, Abkai ordered his reserves to advance only to be pummeled by charging swordsmen and cannonfire. In the ensuing chaos, Abatai was killed. By the end of the afternoon, Abkai was in full retreat and his army was in complete shambles. The khan had lost 30,000 men while Gwanghaegun had lost 9,000. Although the Joseon army had also suffered heavy losses, ultimately Ningguta was a loss the Aisin Gioro clan never recovered from. Gunpowder, not horsepower, prevailed even in the heartland of the nomads.
Despite the victory, Gwanghaegun did not try to chase down the retreating forces. However, Abkai’s army was harassed by the Yehe Jurchens who now were in full rebellion in alliance with Joseon and were further weakened. This allowed Joseon to completely drive out the remaining Jurchen forces from the premises of the Yalu River and occupy the southern portion of the realm. The Yehe Jurchens would become vassals of the king while Hongketai was granted a governorship in the kingdom’s new northern frontier. Abkai launched a concerted campaign against Joseon in 1639 in an attempt to retake the lost lands and devastate the core of the kingdom but failed to defeat an ever-rising Joseon. Gwanghaegun’s invasion and the failures of Abkai descended the khanate to a point of fragile unity, and it would not long last the khan’s death in 1643.
Asia in the aftermath of the 2nd Jin-Joseon War
Gwanghaegun himself would pass away shortly after the war in 1641 at the age of 66. His reign was one marked by the growth of direct royal power at the expense of the aristocracy and neo-Confucian bureaucracy for the better, with great strides towards a stronger, more modernized, and more interconnected kingdom. The 43 year old Crown Prince Yi Ji would succeed him as King Hyeonjo of Joseon. His reign would see the gradual approach of a new power even further to the north of Joseon, the Jurchens, and the Mongols: Russia.
[1]: Without the 1623 coup IOTL, Yi Ji lives on.