Yi Ko


Yi Ko was a military ruler in Korea. During the reign of King Uijong, when the Mushin Rebellion occurred, widespread dissatisfaction had grown among military officials, soldiers, and even common farmers due to the contradictions within the socio-economic system of early Goryeo.
In 1170, when the king made a royal procession to Hwapyeongjae, Yi Ko, who held the rank of Sanwon, expressed his intention to stage an uprising to General Chŏng Chungbu, together with Yi Ŭibang. He gained Chŏng’s agreement.
However, they did not carry out the uprising at Hwapyeongjae. Later, they planned that if the king moved from Yeonbokjeong to Bohyeonwon in Jangdan, Gyeonggi Province, instead of returning to the palace, they would launch the revolt. They made this agreement with Chŏng Chungbu.
As fate would have it, the king’s procession did move to Bohyeonwon. At the Five Gates, the king, intending to appease the military officials, ordered a hand-to-hand combat performance. When General Yi So-eung lost and fled from the match, a young civil official, Han Rae, struck him in the face, knocking him down the stairs. Witnessing this, Yi Ko drew his sword in fury, intending to begin the rebellion immediately, but was dissuaded by Chŏng Chungbu.
As evening fell and the royal carriage passed through the gates, the rebellion was launched. Yi Ko and his allies killed all the civil officials who had accompanied the king and stormed the palace and the Crown Prince’s residence, killing over 50 civil officials. The king, gripped by fear, appointed Yi Ko as Jungnangjang, a middle-ranking commander of the Royal Dragon and Tiger Guard. However, Yi Ko soon joined Chŏng Chungbu and Yi Ŭibang in deposing King Uijong, installing King Myeongjong, and establishing the Goryeo military regime. The three of them divided up King Uijong’s former residences: Gwanbuk Residence, Cheondong Residence, and Gwakjeongdong Residence.
Yi Ko was later appointed Daeganggun and Wiwigyŏng, Minister of the Guards), and concurrently held the office of Chipju with Yi Ŭibang. He was honored as a Pyeoksanggongsin and had his portrait drawn and placed in the royal hall.
Yi Ko, along with Chŏng Chungbu and Yi Ŭibang, advocated for mass executions of civil officials. However, Chŏng Chungbu prevented this plan from going forward.
In 1171, when Grand General Han Sun and Generals Han Kong, Sin Taeye, Sa Chikchae, and Ch'a Chunggyu criticized the military for arbitrarily killing civil officials, Yi Ko and Yi Ŭibang had all of them executed—except for Ch'a Chunggyu, who had a personal friendship with Yi Ŭibang and was thus spared and exiled to a distant province.
Attempting to consolidate power for himself, Yi Go secretly conspired with a group of ruffians, the monk Suhye from Beopunsa Temple, and the monk Hyeonso from Gaeguksa Temple. They drank heavily and Yi Ko promised, “If we succeed in this great plan, you will all receive high positions.” He even forged a royal edict, which drew the suspicion and hatred of Yi Ŭibang.
When the Crown Prince was to perform his coming-of-age ceremony, the king held a banquet at Yeojeong Palace. Yi Ko, acting as Seonhwasa, participated in the banquet. He instructed Hyeonso to gather the ruffians in Suhye’s room at the temple, serve them wine, and conceal weapons in their sleeves to start the rebellion. However, this plan was exposed when the son of Yi Ko’s subordinate, Captain Kim Taeyong, informed his father. Kim Dae-yong then reported it to Naesijanggun, Ch'ae Wŏn.
As a result, Yi Ŭibang, who already despised Yi Ko, waited outside the palace gates and killed him with an iron mace. The royal guards were dispatched to arrest and execute Yi Ko’s mother and his remaining followers. Yi Ko’s father, who had long considered his son a disgrace and disowned him, was spared and merely exiled.

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