Chapter 103: Asiatic Northern War Part III - The Squeeze of Haishenwei
As spring approached, Sakuma Moritora planned his next moves from the reconstructed fortifications at the confluence of the Amur and Songhua rivers. To better combat the forces of Gutai and Gyeongseon, he needed more men. To that end, he sought to march southwards to Haishenwei, recently captured by the Japanese under Sassa Katsutoyo, and unite with the Japanese army of 8,000 before moving on in the war against the Lesser Jin and their peninsular ally. As he made his final preparations and established a permanent garrison at the newly titled Kuromatsu Castle (黒松城), however, Moritora would be preceded by the enemy, who quickly responded to the loss of the key warm water port. Gutai himself would lead an army of 20,000 Jurchens towards the port, joined along the way by 12,000 Joseon troops sent by Hanseong. Meanwhile, Gyeon Be-up designated a small fleet to blockade the port and attempt to bombard the Japanese out of the port. Katsutoyo was quickly alerted of the enemy’s movements when a portion of his men who had occupied the countryside surrounding the port were attacked and driven back into Haishenwei. Eventually, the Joseon fleet could also be seen sailing from the horizon. Moritora himself was notified of these developments by Amur Jurchen sentries that had spied on Gutai’s horde, successfully disguising themselves and evading exposure. He quickly hurried south and alerted Bahai, who was raising a large army near Nurgan.
The Jin-Joseon squeeze of Haishenwei commenced on April 19th. The Japanese warships present at the port held off the enemy ships for a few hours, exchanging blows of smoke and powder until one by one they were either boarded and seized or sunk. Their noble sacrifice allowed Katsutoyo to focus his attention on the land attack, however, and on the first day the Japanese successfully disrupted attempts by the Joseon troops to set up adequate siege weapons. This wasn’t helped by the uselessness of many Jurchen warriors who only knew how to fight as horse archers or lancers on horseback. The following days, however, saw the Japanese begin to struggle as they now faced active assaults from both sides. The sea defenses quickly began to fall apart and one of the enemy ships even attempted an amphibious landing, though it was vigorously rebuffed by Katsutoyo’s men. On land, the Japanese could not prevent the enemy from establishing their siege weaponry. Although Haishenwei had a sizable garrison, the pincer attack was effective and it looked like the port would fall within a week.
This assumption would be challenged with the arrival of Moritora and his army of 14,000, consisting of 5,500 Japanese infantry and cavalry, 8,000 Amur Jurchens, and 500 Ainu cavalry along with a handful of cannons. Gutai, despite already besieging Haishenwei, prepared to confront the enemy, confident that his numbers would win the day and simultaneously continue to pressure Katsutoyo’s men. 24,000 were fielded against the Japanese field army, composed of 8,000 Joseonites and 16,000 Jurchens. 4,000 Jurchen horse archers screened the army, while a mix of Joseon and Jurchen infantry concentrated in the center. Heavy Joseon cavalry, the elite of the kingdom’s military, manned the wings alongside Gutai’s best horsemen while more Jurchen cavalry made up the rest of the wings and the center. Gutai himself would oversee the battle surrounded by his guards and reserves. Meanwhile, on the Japanese-Amur side, 3,000 horse archers similarly screened the rest of the army. 4,000 Japanese musketeers commanded by Mogami Yoshisato formed the center backed by 1,000 Jurchen melee infantry, while Moritora surrounded himself with his Ainu cavalry, Oshu warriors, and supporting Jurchen horsemen on the left. The right, meanwhile, was composed entirely of Jurchen horse archers and lancers led by young chieftain Bakedu. The battle would take place in the vicinity of Lake Bogatoye just north of the port on April 26th.
Salmon = Japanese, Green = Amur, Blue = Joseon, Brown = Lesser Jin
The battle began with the horse archers at the frontlines skirmishing with one another. As the outnumbered Amur Jurchens began to break, the Japanese center moved forward, firing swift volleys upon the unsuspecting enemy who quickly retreated and melted into their fellow ranks. Both sides then initiated a general charge. On the Japanese left, Moritora as usual directly led his men towards the enemy cavalry. Despite being outnumbered 2 to 1, the skill and prowess of the Japanese cavalry allowed them to hold their own, their pistols surprising many horses. Similarly to how they functioned as shock infantry in the Manji War, Ainu cavalry swung around their long harpoons and several Jurchens fell victim to impalement by the Ainu harpoons. A similar case was taking place in the middle, where the discipline and experience of the Japanese musketeers allowed the Japanese to stand their ground. The situation was very different on the Japanese right where the Jin-Joseon cavalry almost immediately began to push back the Amur Jurchens. Eventually, their sheer numbers won the day and the main Amur Jurchen contingent began a full retreat, and they turned in anticipation of flanking and routing the hypothetically vulnerable Japanese infantry. Other developments on the battlefield, however, had taken place that would not allow such a clean sweep by Gutai’s army. To shore up the center, the Amur infantry reserves had joined the battle and this proved decisive as the Jin-Joseon infantry also broke into a retreat, buckling under intense pressure. Although Gutai’s reserve cavalry attempted to salvage the situation, they were no match for the cannonfire and musket volleys of the Japanese. This enabled some of the infantry to respond to the Jin-Joseon right’s momentum as they split off from the main body and reinforced the line of cannons being turned towards the impending flanking cavalry charge. This worked and Jin general Laihu decided to retreat and protect his khan’s position. The Japanese infantry core also retreated in response, and the battle began to end. Moritora was still fighting intensely against the Jin-Joseon right but both sides would withdraw as soon as they saw everyone else cease fighting and retreat.
The battle ended in a draw. Casualties mounted to 2,500 for the Japanese-Amur army and 3,000 for the Jin-Joseon army. However, while Moritora had held his own against a larger army, he could not afford as many casualties and had failed to rout the khan’s force. Meanwhile, the diversion of men enabled Katsutoyo to skirmish and weaken the land besiegers but his men were quickly running out of provisions and the bombardments from the sea remained relentless. Hearing the news of the Battle of Bogatoye only confirmed his worst fears. Therefore, Katsutoyo devised a course of action that would save as many of his men’s lives as possible. He charged his uncle Katsutane (佐々勝種) with escorting the bulk of the army under the cover of darkness. 200 men, including himself, however, would remain to torch the dock and sally out on land. On the morning of April 29th, after Katsutane had secretly left along with 5,000 men, Katsutoyo executed his own role in his plan and would ultimately commit seppuku in the port, symbolically taking responsibility for his failure to hold down Haishenwei. He was only 32. With his death and the Japanese abandonment of the port, Haishenwei was taken back by the Lesser Jin.
Sassa Katsutane successfully escorted the survivors to Sakuma Moritora’s camp, albeit bringing bad news. A shocked Moritora accepted the hair knot of Katsutoyo with sorrow and promised to live and win the war so that it could be presented to Katsutoyo’s widow. After this, Moritora retreated north once again, hoping to gather more men and coalesce forces with Bahai. Beyond the surroundings of Haishenwei, the forces of the Lesser Jin and Joseon continued to gradually conquer the Amur river valley and much work needed to be done to not only defend the Amur Khanate’s remaining territories but also drive the enemy out. What no one knew at the time though was that a new player was about to enter the fray in the region, a force beholden to neither side.