In 399 Ko-gu-ryŭ sent an envoy to the Yŭn capital to pay her respects, but the king of that country charged Ko-gu-ryŭ with ambitious designs and sent an army of 30,000 men to seize the fortresses of Sin-sŭng and Nam-so, thus delimiting the frontier of Ko-gu-ryŭ to the extent of 700 _li_. They carried back with them 5,000 “houses,” which means approximately 25,000 people, as captives. It is difficult to believe this enumeration unless we conclude that it means that the people living within the limit of the 700 _li_ were taken to be citizens of Yŭn.
The fifth century of our era dawned upon a troubled Korea. The tension between the three rival powers was severe, and every nerve was strained in the struggle for preeminence. In 402 Nă-mul, the king of Sil-la, died and Sil-sŭng came to the throne. He sent out feelers in two directions, one toward Ko-gu-ryŭ in the shape of a hostage, called by euphemism an envoy, and another of the same sort to Japan; which would indicate that Sil-la was still suffering from the depredations of the Japanese corsairs. The envoy to Ko-gu-ryŭ was the king’s brother, Pok-ho, and the one to Japan was also his brother, Mi-sa-heun. We remember that Păk-je already had an envoy in Japan in the person of the king’s eldest son Chön-ji. Now in 405 the king of Păk-je died. Chön-ji was the rightful heir but as he was in Japan the second son should have assumed the reins of government. As a fact the third son Chŭng-nye killed his brother and seized the scepter. Hearing of his father’s death, Chön-ji returned from Japan with an escort of a hundred Japanese, but learning of his brother’s murder he feared treachery against himself and so landed on an island off the coast where he remained until the people, with a fine sense of justice, drove Ch’ăm-nye from the throne and welcomed back the rightful heir.