Song Yu-in

Song Yu-in (? – October 18, 1179) was a Goryeo military official who served the Goryeo military regime. The son-in-law of military ruler Chŏng Chung-bu, he was killed when Kyŏng Tae-sŭng took control of the government from his father-in-law.

Biography
Song Yu-in was the son of a man who died defending Goryeo during the reign of King Injong. Due to his father's death on behalf of the nation, Song Yu-in was granted the rank of executive captain via protected appointment. Song rose through the ranks to become tae'ja pujiyu then general of the guards. He married the ex-wife of a Song dynasty merchant. Despite being from the lowly cheonmin class, Song's wife was wealthy. Song was able to use his wealthy wife's money to bribe the eunuchs and obtained a government post. By the 1170 military coup, Song had achieved the rank of grand general.

Due to Song's connections to the civilian officials, Song was disliked by the other military officials who despised the civilian officials for their treatment of the Goryeo military. After the 1170 Goryeo military coup, Song abandoned his wife and married the daughter of Chŏng Chung-bu, one of the ringleaders of the coup, in order to avoid persecution. Song would be appointed the military commissioner of Seobukmyeon. However, when he was unable to deal with local revolts, he feigned illness and resigned from the role, and was replaced by General U Hak-yu.

On January 23, 1175, Song Yu-in was appointed as vice commissioner of the Security Council and the minister of war. On January 30, Song was replaced as the minister of war by Chin Chun, and Song was appointed as the minister of justice instead. Song would later also be promoted to Assistant Executive in Political Affairs, and by the request of his wife, the daughter of Chŏng Chung-bu, he was promoted to Secretariat for State Affairs Vice Director.

In 1178, when Chŏng retired from his government offices, Song Yu-in was given the office of the Vice-Director of the Chancellery. Song was also given permission from King Myeongjong to use Suchang Palace as Song's own residence. In 1179, he impeached Confucian scholar-officials Mun Kŭk-kyŏm and Han Mun-jun, demoting them from their positions at the Security Council. On October 18, Song and his father-in-law were killed by Kyŏng Tae-sŭng who opposed the rule of Chŏng and his family.