Gen. Ch‘oe had acquired so much power that he was in reality the ruler of the land, holding much the same position that the Shogun of Japan is said to have occupied. He may not inappropriately be styled the Shogun of Koryŭ. For this reason the king desired to get him out of the way. To this end he put upon his track a number of monks, but as they began by attacking his servant he quietly slipped into a chest and they could not find him. His body-guard became aware of his predicament and forced the palace gates, killing right left; and they would have killed the king had not the wily old general stepped out of his hiding place and prevented it. The latter banished the king to Kang-wha and the crown prince to Chemulpo and set upon the throne one Chong, whose posthumous title is Kang-jong.
The only event recorded of this reign is the arrival of an envoy from the Kin court, who wanted to enter the palace by the central or royal gate. He insisted upon it until he was asked the question “If you enter by the royal gate, by what gate would your master enter should he come here?” This silenced him.
Kang-jong was succeeded in 1214 by his son Chin, posthumous title Kang-jang. This was destined to be the longest and by far the most eventful reign of the dynasty for it lasted forty-five years and witnessed the great Mongol invasion.
The Kin power was now trembling under the Mongol onslaught and envoys came demanding aid from Koryŭ in the shape of rice and horses. The king ostensibly refused but allowed the envoys to purchase rice and carry it away with them.
Again a dark cloud hung over Koryŭ’s northern border. It was not the Mongols as yet, but the remnant of the Kitan forces who were unable to withstand the Mongols and so had fled south into Koryŭ territory. At first the Koryŭ forces were able to keep them in check but as they came in ever increasing numbers they broke down all opposition and were soon ravaging Whang-hă Province, making P‘yŭng-yang their headquarters. The lack of Koryŭ soldiers was so evident that men of all classes, even the monks, became soldiers. It was of no avail. They were cut down like stubble and Whang-ju fell into Kitan hands. The enemy was soon only eighty _li_ from the capital. Consternation reigned in the city and the people all procured swords or other weapons and manned the walls.