Goryeo literatus and chief minister, author of the Collected Works of Yi Sanggukkuk and the epic Dongmyeongwangpyeon; pen name Baegun Geosa; posthumous title Munsun

| Life | 1168 ~ 1241 |
| Era | 고려 중기 |
| Clan | 여주 이씨 |
Yi Gyu-bo (1168-1241) was a mid-Goryeo literatus and chief minister. His first name was Inji, courtesy name Chunggyeong, pen name Baegun Geosa (Hermit of the White Clouds), and posthumous title Munsun. The Munsun-gong branch of the Yeoju Yi clan reveres him as its mid-founder; Korean Wikipedia gives his seat as Hwangryeo, a historical name of Yeoju. His birth year is given as 1168 or 1169 depending on the source, and his father was Yi Yun-su, a vice-minister of the Board of Revenue.
He read widely from youth and passed the preliminary examination in 1189 and the ministry examination in 1190, but office did not come quickly. He lived for a time on Mt. Cheonma near the capital, where he wrote verse and is said to have composed the epic Dongmyeongwangpyeon on the founding of Goguryeo. He joined a campaign against the Gyeongju (Dongkyeong) revolt in 1199, and in 1207 wrote a pavilion record at the order of Choe Chung-heon, which opened his official career.
He served as Right and Left Remonstrator, was demoted in 1219 to Magistrate of Gyeyang, was briefly exiled to Wido in 1230, and was then recalled to rise through Grand Academician, Jeongdangmunhak and Chamjijeongsa, retiring in 1237 as Munhasirang Pyeongjangsa. He drafted diplomatic letters to the Mongols and died on Ganghwa Island in 1241. He is said to have called himself the "master of three obsessions": poetry, the geomungo and wine.
Dongmyeongwangpyeon is an epic on King Dongmyeong (Jumong), founder of Goguryeo, and is read as asserting Goryeo as Goguryeo's legitimate heir. It is said to have influenced later works such as Yi Seung-hyu's Jewang Ungi and the Yongbi Eocheon-ga.
Against a poetics built on borrowing old phrases, he argued for "new meaning" (sinui-ron), expressed in one's own voice. Works introduced include the wine allegory Gukseonsaengjeon and the palindromic poem "Miinwon". A contemporary writer of the age was Yi In-ro.
When demoted to Magistrate of Gyeyang in 1219 he left writings tied to Jao Pavilion on Mt. Gyeyang, and a road in Bupyeong, Incheon, bears his name. After retiring in 1237 he is said to have taught younger scholars on Ganghwa, and he died in 1241 before the publication of his collected works, hurried by Choe I, was finished. Ganghwa has his tomb, a shrine and a literary museum.
His tomb is at Giljik-ri, Gilsang-myeon, Ganghwa County, Incheon, and is listed as an Incheon municipal monument.
The Munsun-gong line is organized into the Panseo-gong, Saganggong and Noksa-gong branches founded by his sons Yi Ham, Yi Jing and Yi Je.