When the whole army had effected a crossing the Emperor sent 1200 troops to occupy the fortified town of Liao-tung but the Ko-gu-ryŭ general, Eul-ji Mun-dŭk, hastened thither and drove back this detachment of Chinese in confusion. The Emperor learned of the retreat and proceeded toward the scene of action. When he came up with the flying detachments of his defeated force he severely reprimanded the generals in charge and chided them for being lazy and afraid of death. But it was now late in June and the rainy season was at hand, so the Emperor with his whole army went into camp at Yuk-hap Fortress a little to the west of the town of Liao-tung, to await the end of the wet season.
He was unwilling however to let all this time pass without any active work; so he sent a fleet of boats by sea to sail up the Ta-dong River and attack P’yüng-yang. This was under the leadership of Gen. Nă Ho-a. Landing his force on the bank of the Ta-dong, sixty li below the city, he enjoyed there a signal victory over a small force which had been sent to head him off. This made the general over-confident and in spite of the protests of his lieutenants he marched on P‘yŭng-yang without an hour’s delay. With twenty thousand troops he went straight into the town, the gates being left wide open for him. This was a ruse on the part of the Ko-gu-ryŭ forces. A strong body of Ko-gu-ryŭ troops had hidden in a monastery in Nă-gwak Fort on the heights within the city. The Chinese found themselves entrapped and Gen. Nă was forced to beat a hasty retreat with what forces he had left, and at last got back to Hă-p’o (harbor) in Liao-tung. What the Emperor said to him is not known but it could not have been flattering.
The rainy season had now come and gone and the main plan of the invasion was ready to be worked out. It was necessary for the Emperor to spread out his force over the country in order to find forage, and so, in approaching the borders of Ko-gu-ryŭ, it was decided that they should come by several different routes. Gen. U Mun-sul led a detachment by way of Pu-yŭ, Gen. U Chung-mun by way of Nang-nang, Gen. Hyŭng Wŭn-hang by way of Yo-dong, Gen. Sŭl Se-ung by way of Ok-jŭ, Gen. Sin Se-ung by way of Hyŭn-do, Gen. Chang Keun by way of Yang-p’yăng, Gen. Cho Hyo-jă by way of Kal-sŭk, Gen. Ch’oe Hong-seung by way of Su-sung, Gen. Wi Mun-seung by way of Cheung-ji. It is said that they all rendezvoused on the western bank of the Yalu River, but if so there must have been great changes in the position of these wild tribes. It is more than probable that like the North American Indians they had moved further and further back from their original lands until they were far beyond the Yalu and Tumen rivers.
In the early autumn of 612 the whole army lay just east of the Yalu River.
The king of Ko-gu-ryŭ sent Gen. Eul-ji Mun-dŭk to the Chinese camp to tender the Emperor a pretense of surrender but in reality to spy out his position and force. When he appeared the Emperor was minded to kill him on the spot but thought better of it and, after listening to what he had to say, let him go. Not an hour after he had gotten beyond the Chinese pickets the Emperor changed his mind again and sent in pursuit of him; but the general had too good a start and made too good use of his time to allow himself to be retaken.
And now appeared one of the disadvantages of being far from one’s base of supplies, and in an enemy’s country. Some weeks before this each Chinese soldier had been given three bags of rice and told that he must carry them on the march, besides his other necessary accoutrements. Death was to the penalty of throwing any of it away. The result was that most of them buried a large part of the rice in their tents and so escaped detection. Now they were short of provisions, while the generals thought their knapsacks were full of rice. The Ko-gu-ryŭ Gen. Eul-ji, who had been in their camp, however, knew about it. He entered upon a geurilla[geurilla] warfare with the object of luring the enemy far into Ko-gu-ryŭ territory and then cutting them to pieces at leisure. To this end he made a feigned retreat several times each day, thus giving the enemy confidence and blinding them to his own strength. It was decided that a Chinese force of 305,000 men under Gen. U Chung-mun should proceed straight to P’yŭng-yang. It seemed wholly unnecessary that the whole army of 1,130,000 men should undergo that long march when only a pusillanimous enemy barred the way.
On they came toward the capital without meeting anything but a few skirmishers, until they reached the Sal-su, a stream only thirty li from P’yŭng-yang. Crossing this the Chinese went into camp for a few days to recover from the fatigue of the rapid march before attacking the town.
At this point Gen. Eul-ji began operations. He wrote a very humble letter sueing[sueing] for mercy. When the Chinese general received this, his course of reasoning must have been something as follows: “My forces are completely exhausted by this long march; the provisions are almost gone; I shall find the capital defended by desperate men; it may be that I shall be handled as roughly as were the forces of Gen. Nă. I will accept this submission and start back in time to reach the Yalu before my provisions are entirely gone. I will thus spare my army and gain the desired end as well.”
Whether this was his course of reasoning or not, sure it is that he accepted the submission tendered him and put his army in motion toward the Yalu. But before his forces had gone a mile they found themselves attacked on all sides at once by an unseen foe which seemed to fill the forests on either side the road. When half the army had gotten across the Sal-su the other half was fiercely attacked and cut to pieces or driven like dumb cattle over the face of the country, where they were butchered at leisure. The retreat became a flight, the flight a rout, and still the Ko-gu-ryŭ soldiers hung on their flanks like wolves and dragged them down by scores and hundreds. It is said that in a single day and night the fugitive Chinese covered four hundred[hundred] and fifty li, and when the remnant of that noble army of 305,000 men that had swept across the Yalu went back across that historic stream it was just 2700 strong. Over 300,000 men had perished along the hill-sides and among the forests of Ko-gu-ryŭ. The Emperor in anger imprisoned the over-confident Gen. U Chung-mun.
Meanwhile what of Păk-je? She had promised that she would rise and strike Ko-gu-ryŭ simultaneously with the Emperor, but when the moment for action came, like the paltroon[paltroon] that she was, she waited to see which side would be most likely to win in the end. When the Chinese fled back to the border in panic Păk-je quietly stacked her arms and said nothing about attacking her neighbor.