Having made Ch‘oe Yŭng general-in-chief of the expedition, the king accompanied the army north to Pong-ju, now Pong-san. Gen. Ch‘oe never divulged the fact that this was an army of invasion but told all the troops that they must be strong and brave and ready for any work that might be given them to do. Gen. Yi T‘ă-jo was made lieutenant-general in connection with Gen. Ch‘oe. He made a powerful plea against the war and the main points of his argument are preserved to us. His objections were (1) It is bad for a small country to attack a powerful one. (2) It is bad to make a campaign in summer when the heavy rains flood the country, rendering the transporting of troops almost impossible and decimating them with disease. (3) It is bad to drain off all the soldiers from the country when the Japanese are so constant in their ravages. (4) The heat and moisture of summer will spoil the bows and make them break easily. To all these objections the king replied that having come thus far the plan must be carried out. Gen. Yi hazarded his neck by demurring; still asserting that it would mean the overthrow of the kingdom. The king in rage exclaimed “The next man that advises against this war will lose his head.” This was an end of the debate and as the council of war dispersed the officers saw Gen. Yi weeping, and to their questions he answered “It means the destruction of Koryŭ.” The Yalu was quickly bridged and Gen. Yi in company with one other general started north from P‘yŭng-yang with 38,600 troops, 21,000 of whom were mounted. At the same time the king discarded the Ming calendar, dress and coiffure. The Mongol clothes were again adopted and the hair cut. The Japanese knowing that the troops had gone north, entered the open door thus invitingly left ajar and seized forty districts.