The closing years of sixteenth century found Choson Korea beset with considerable political and economical difficulties. Incessant conflicts between political parties had led to corruption, which in turn had led to confusion in the tax system. The effects of inter-party wrangling had inevitably spread to regional governments, destabilizing national politics as a whole. The unjust and unreasonable appointment of officials, and the poor administration which naturally followed, stirred up feelings of distrust and resentment in the people. As a result, there was a decline in military discipline, and national defense was put seriously at risk.

Meanwhile, across the Korea Strait, Toyotomi Hideyoshi had in the year 1590 put an end to 150 years of civil conflict by successfully unifying Japan under his rule. As he was dealing with the task of unification, he had looked for a way to dilute the power of feudal lords (daimyo), who at that time represented the most serious threat to his authority, and thereby reinforce the power of the central government. With this end in mind, he planned the invasion of neighboring countries so that he would be better able to control their internal feuding and divert the energy and attention of the daimyos abroad. At first, he requested the Korean King to permit free passage through Korea for the swift movement of his army into Ming China. Korea sent two-man mission to observe Hideyoshi’s true intention and the likelihood of Japanese invasion, but they returned with conflicting opinions. Hwang expressed the possibility of invasion, while Kim thought little of the possibility. The King and the ruling classes were not alarmed. They laughed away the Japanese approaches and ignored the possibility of war. When his overtures met with steadfast refusal, Toyotomi Hideyoshi resolved to invade the Korean peninsula .

Korea, a nation for centuries accustomed to peace, was therefore completely unprepared when Japan presently invaded with 160,000 troops, in the April of 1592. Before the Japanese, with their superior numbers, training, and new arms called muskets, the poorly-equipped Korean military were as good as helpless. The southern defense perimeter was breached with a matter of days, and the forces of Japan began to make their way the north without facing any serious difficulty.

The Korean King, Son Jo, fled with his son to Pyung Yang on April 30; two days later the Japanese reached the capital Seoul, only eighteen days having passed since their unopposed landing in Pusan. As the Japanese army continued their relentless advance northwards, defeating every Korean force which had the courage to face them, King Son Jo and his Court abandoned the defense of Pyung Yang and fled again to Uiju, at the northern tip of the Korean peninsula. The Korean people were furious with the incompetence and irresponsibility of King and his Court. After only two months, the entire country had all but fallen to its victorious Japanese invaders.