Meanwhile there was going on in the south a sort of geurilla warfare against the Japanese. It was led principally by Kim Tŭk-nyŭng, a self-made man who had the confidence of the prince. This man had put his whole fortune into the cause and had himself fitted out 5,000 men. His method was to pass from place to place with great rapidity and strike the enemy when they were least expecting attack. In this way he earned from the Japanese the name “The Flying General.” He is said to have been uniformly successful.
Of another ilk were Song U-jin, Yi Neung-su and Hyŭn Mong. These gathered about them bands of desperate men and went about the country looting and burning. In Seoul there was consternation. At any moment one of these bands might enter the city and work their will. The Crown Prince, a cause of great uneasiness, was still at Chŭn-ju and for aught anyone knew he might be plotting the overthrow of the government. In fact this impression was so strong that the highwaymen dared to write to him complaining of the king and asserting that they were going to make a clean sweep. The implication was plain, that they intended to put the prince upon the throne. The solicitude of the people in Seoul took form in the rumor that Yi Tă-hyŭng himself, the Minister of War, was in league with the rebels. For forty successive days this injured minister went and knelt at the palace gate and begged that the king would have him executed, as he could not endure the charge of unfaithfulness.
It was customary for the emperor to nominate an heir apparent for the Korean throne, but at the beginning of this war it had seemed necessary to appoint one immediately and so the king had informally promised the prince that he should be king. The latter now demanded that this be confirmed by the emperor and a messenger was sent to the Chinese court for that purpose; but as the emperor had no son himself except by a concubine and was loath to put him on the throne of China, so he was unwilling to see this prince put on the throne of Korea. The result was that he sent back a prompt refusal, which for the time dashed the hopes of the ambitious prince.
It appears that the rebuke which the emperor administered to the king was in some senses deserved. The king after all his wearisome exile in the north, probably paid more attention to the pleasures of peace than was for his own good or the good of the country. If so the rebuke had its effect, for the king immediately roused himself and set to work reorganizing the finances of the country and putting the army on a better working basis. Hitherto the revenue had all been collected in rice but now he allowed the revenue to be collected in any kind of produce, and the collection of it was farmed out to various individuals, a practice which at the time may have had its good points but which at the same time had within itself very bad possibilities. The reorganization of the army was a matter of great importance and the king set himself to it with a will. Heretofore each general had had his own following and there was no central power nor seat of authority. Each body of troops followed the caprice of its leader with no reference to any general plan. Before the Chinese general Yi Yŭ-song left he put into the hands of the king a book treating of the art of war, a work written by Ch’ŭk Kye-gwang. This book the king put into use and appointed Cho Kyŭng and Yu Sŭng-nyong to have charge of the whole matter of military reorganization. In order to put the new plan into operation a large number of poor and destitute soldiers were gathered. They had to pass a physical test which consisted in lifting a rice bag full of earth, and of leaping over a wall as high as their heads. In ten days two thousand men were found who endured the test. The drill consisted of three parts, (1) firing with guns, (2) shooting with bow and arrow, (3) using the battle axe. In time these men became the royal guard and escort. The number gradually increased to 10,000, 2,000 being attached to each of the government departments. The whole force was divided into two parts and while one part was drilling in the city the other was set to work farming in the suburbs. In this way they raised the food necessary for the sustenance of the whole force. The plan was extended to the country, and teachers were sent to practice the country soldiers. It became a species of militia. From this time the quality and discipline of the Korean army improved in a marked degree.