Yi Ko (; ?âÂÂ1171) 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 (24th year of King Uijong's reign), when the king made a royal procession to Hwapyeongjae (Ã¥ÂÂå¹³é½Â), Yi Ko, who held the rank of Sanwon (a minor court official), expressed his intention to stage an uprising to General Chà Âng Chungbu, together with Yi à ¬ibang. He gained Chà ÂngâÂÂs agreement.
However, they did not carry out the uprising at Hwapyeongjae. Later, they planned that if the king moved from Yeonbokjeong (延ç¦ÂäºÂ) to Bohyeonwon (æ®賢é¢) in Jangdan, Gyeonggi Province, instead of returning to the palace, they would launch the revolt. They made this agreement with Chà Âng Chungbu.
As fate would have it, the kingâÂÂs procession did move to Bohyeonwon. At the Five Gates (ì¤문), the king, intending to appease the military officials, ordered a hand-to-hand combat performance (ì¤ë³ÂìÂÂë°Âì). When General Yi So-eung (ì´ìÂÂìÂÂ) lost and fled from the match, a young civil official, Han Rae (ÃÂÂ뢰), 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 Chà Âng 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 PrinceâÂÂs residence, killing over 50 civil officials. The king, gripped by fear, appointed Yi Ko as Jungnangjang (ä¸ÂéÂÂå°Â), a middle-ranking commander of the Royal Dragon and Tiger Guard (ìÂÂìÂÂì©Ã¸군 é·¹æÂÂé¾ÂèÂÂè»Â). However, Yi Ko soon joined Chà Âng Chungbu and Yi à ¬ibang in deposing King Uijong, installing King Myeongjong, and establishing the Goryeo military regime. The three of them divided up King UijongâÂÂs former residences: Gwanbuk Residence (館åÂÂå® ), Cheondong Residence (æ³Âæ´Âå® ), and Gwakjeongdong Residence (è¿äºÂæ´Âå® ).
Yi Ko was later appointed Daeganggun ((), Grand General) and Wiwigyà Âng (), Minister of the Guards), and concurrently held the office of Chipju (Ã¥ÂጴÂ, a role combining administrative and military authority) with Yi à ¬ibang. He was honored as a Pyeoksanggongsin (å£Âä¸ÂÃ¥ÂÂè£, "Meritorious Subject Painted on the Wall") and had his portrait drawn and placed in the royal hall.
Yi Ko, along with Chà Âng Chungbu and Yi à ¬ibang, advocated for mass executions of civil officials. However, Chà Âng Chungbu prevented this plan from going forward.
In 1171, when Grand General Han Sun (ÃÂÂìÂÂ) and Generals Han Kong (ÃÂÂê³µ), Sin Taeye (ì ëÂÂìÂÂ), Sa Chikchae (ì¬ì§Âì¬), and Ch'a Chunggyu (ì°¨ì¤Âê·Â) criticized the military for arbitrarily killing civil officials, Yi Ko and Yi à ¬ibang had all of them executedâÂÂexcept for Ch'a Chunggyu, who had a personal friendship with Yi à ¬ibang 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 (akso, æ¡å°Â), the monk Suhye (ä¿®æ ) from Beopunsa Temple (æ³Âé²寺), and the monk Hyeonso (çÂÂç´ ) from Gaeguksa Temple (éÂÂÃ¥ÂÂ寺). They drank heavily and Yi Ko promised, âÂÂIf we succeed in this great plan, you will all receive high positions.â He even forged a royal edict (chesà Â, å¶æ¸), which drew the suspicion and hatred of Yi à ¬ibang. When the Crown Prince was to perform his coming-of-age ceremony (ê´Âë¡Â, å 禮), the king held a banquet at Yeojeong Palace (éºÂæ£宮). Yi Ko, acting as Seonhwasa (宣èÂ񄫨, Master of Ceremonies), participated in the banquet. He instructed Hyeonso to gather the ruffians in SuhyeâÂÂs 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 KoâÂÂs subordinate (kusa, 驠使), Captain Kim Taeyong (ê¹ÂëÂÂì©), informed his father. Kim Dae-yong then reported it to Naesijanggun (å §ä¾Âå°Âè»Â, Commander of the Royal Guards), Ch'ae Wà Ân (ì±ÂìÂÂ).
As a result, Yi à ¬ibang, 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 KoâÂÂs mother and his remaining followers. Yi KoâÂÂs father, who had long considered his son a disgrace and disowned him, was spared and merely exiled.