Military governor of Hamgil Province who helped open the Six Garrisons with Kim Jong-seo and rose in arms after the 1453 coup before being killed; pen name Wonbong; posthumous title Chung-gang
| Life | 1399 ~ 1453 |
| Era | 조선 전기 |
| Clan | 인천 이씨 |
Yi Jing-ok (李澄玉, 1399-1453) was an early Joseon military officer from Incheon, pen name Wonbong, posthumous title Chung-gang. He was born in Yangsan, South Gyeongsang, the second son of Yi Jeon-saeng of the Privy Council. A descendant of Marquis Yi Heo-gyeom, his grandfather Yi Man-yeong served late Goryeo and was later honoured as a supplementary merit subject of Joseon. He is said to have captured a live tiger as a boy and was known as an incorruptible official.
He entered service as a guardsman in 1414, passed the military examination in 1416 and placed first in the royal military examination of 1418. As a young man he became commander of Yeongbuk garrison and was nicknamed the 'boy commander'. Under King Sejong he followed Kim Jong-seo defending the northern frontier, serving as commander of Gyeongwon, magistrate of Hoeryeong and Gyeongheung and Hamgil military governor, and contributed to subduing the Jurchen and opening the Four Garrisons and Six Forts. The Jurchen are said to have called him 'the big boar with tusks'. An anecdote tells how he ignored the excessive tribute demands of the Ming envoy Yun Bong.
After Prince Suyang killed Kim Jong-seo in the 1453 coup and took power, Yi was dismissed and Bak Ho-mun sent as successor. Hearing of the coup on his way to the capital, he turned back, killed Bak and at Jongseong proclaimed himself 'Emperor of the Great Jin', but was attacked and killed with two sons by the Jongseong magistrate Jeong Jong and Yi Haeng-geom (aged 55). Chae Je-gong later argued the rising was for King Danjong, but assessments differ. His third son Yeon-won was saved by his nurse and hid near Gyeongju, and his descendants continued as the Chung-gang branch of the Incheon Yi. His rank was restored in 1791 with the title Chung-gang, revoked again after Jeongjo's death, and he is said to have been rehabilitated in 1908.
He placed first in the 1418 royal military examination and became commander of Yeongbuk garrison in his youth, earning the nickname.
He followed Kim Jong-seo in opening the Four Garrisons and Six Forts and defending against the Jurchen.
Dismissed after the coup, he killed his successor Bak Ho-mun and rose in arms but was killed at Jongseong. The 'Great Jin emperor' title comes from the Annals; some read the rising as being for King Danjong.
His tomb was not confirmed. He is enshrined at Sungmojeon in Donghaksa on Mt. Gyeryong and the Danjong accompanying altar at Jangneung in Yeongwol.
Descendants of his third son Yeon-won are said to continue as the Chung-gang branch of the Incheon Yi (records say they briefly used seats such as Chosan or Chogye).