The reign of this second king of Koryŭ starts with the statement that the king gave his own sister to his brother for a wife. It was one of the peculiar institutions of the dynasty that whenever possible the king married his own sister. In this instance he gave his sister to his brother, but the king had probably already married another of his sisters. This custom, which has prevailed in other countries besides Korea, notably in ancient Egypt, rests upon the assumption that by marrying one’s own sister more of royalty is preserved in the family and the line is kept purer, the royal blood not being mixed with any of baser quality. We are told that, in order to make it seem less offensive, the sister, upon marrying her brother, took her mother’s family name. This shows that the custom was looked down upon, else this device would not have been resorted to. We find also that the kings of Koryŭ were accustomed to have more than one real wife, contrary to the custom of the present dynasty. We read that this king, who had none of the elements of his father’s greatness, took as his sixteenth wife the daughter of one Wang-gyu and by her had a son. Through her influence Wang-gyu had risen to the position of prime minister and it was his ambition to see his daughter’s son ascend the throne. It had been the king’s plan to give the throne to his brother Yo and the prime minister began by plotting against the life of this possible successor. The king learned of this and frustrated it by immediately abdicating in favor of his brother. Wang-gyu seems to have possessed considerable power independently of the king for we learn that he not only was not punished but that he continued to plot against Yo even after he had assumed the reins of power. An assassin whom he had hired to kill the king was himself killed by the king while attempting to carry out the deed. When the king fell ill he was advised to move secretly to another palace for safety. He did so and that very night the myrmidons of Wang-gyu broke into the palace that he had left, but found that their bird had flown. In spite of all this the king did not proceed against his minister but went about with an armed escort. This signal failure to punish a traitor is said to have been the reason why, during the whole dynasty, the officials overruled the king and made a puppet of him. In fact many times during the dynasty we find the condition of affairs somewhat like those in Japan where the emperor himself had little practical power but the government was carried on by a shogun. But at last this Wang-gyu met his deserts for he was banished to Kap-whan and there executed, and with him 300 men who had been in his pay.