Joseon’s Mo’ryeon-wei conquest agitated the Jurchens significantly. What concerned them most was the possible continuation of Joseon’s conquest. After its conquest of Mo’ryeon-wei, Joseon also tried to approach the Jurchens in a cautious manner, fearing Mo’ryeon-wei and Jian’zou-wei might join forces.
After the Mo’ryeon-wei conquest, however, there was a series of discussions inside Joseon on further conquests. Li Manzhu strived to improve relations with Joseon, providing Joseon with critical intelligence upon Wild Jurchens, in an attempt to avoid Joseon’s conquest. Nevertheless, Joseon maintained its plan to gain full control of Li Manzhu of Jian zou-wei, that had been in existence since King Sejong’s reign, with its diplomatic and military power.
This led Li Manzhu to finally send an envoy to Ming to ask protection of Jian’zou-wei from Joseon’s attack. The Ming Emperor accepted his request and stopped Joseon’s dispatch of its troops. As Joseon assured Li Doori that it had no intention of conquering Jian’zou-wei, and the Ming Dynasty took measures as requested, the Jian’zhou Jurchens concluded that a threat of Joseon’s conquest disappeared.
King Sejo later ordered his troops consisting of 15,000 infantry soldiers to conquer Jian’zhou-wei. Joseon’s dispatch of troops at the time seemed as an attack launched in response to a massive invasion from the Wild Jurchens. The fact that Joseon decided to dispatch its troops only three days after it received a report of the Wild Jurchen invasion, however, implies that Joseon’s discussions and preparation for a dispatch had already been well underway.
Joseon’s conquest came to a halt, as Lee Se eae led a revolt not long after the decision was made. Meanwhile, expressing its intentions to suppress Jian’zhou-wei, Ming asked Joseon to dispatch its troops. Although the aftermath of the revolt was not completely subdued, King Sejo showed his will to dispatch its troops as requested by Ming.
King Sejo used Ming s request for Joseon’s dispatch of troops to conquer Jian’zhou-wei as a chance to achieve Joseon’s diplomatic goals. While seemingly accepting Ming’s request, Joseon rather made use of this opportunity to get rid of Li Manzhu and his son who had served as pivotal figures among the Jian’zhou Jurchens. Joseon eliminated its enemy’s chief, and achieved a critical factor which would determine the success or failure of a conquest.
Ming’s dispatch of troops was intended to keep Joseon in check, which was at the time expanding its influence over the Jurchen region by conquering it, and to strengthen Ming’s control over the region. Joseon during King Sejo’s reign successfully maintained its influence over the Jurchen region by accepting Ming’s request and at the same time capturing and eliminating the enemy’s chief, which clearly demonstrated a successful conquest. Joseon at the time maintained its control of the Jurchen region while continuing to demonstrating submission to the Ming.