Late-Goryeo civil official and Neo-Confucian scholar; founding ancestor of the Ikjae line of the Gyeongju Yi clan

| Life | 1287 ~ 1367 |
| Era | 고려 |
| Clan | 경주 이씨 |
His courtesy name was Jungsa, his pen names Ikjae and Yeogong, and his posthumous title Munchung. Gifted in letters from childhood, he passed through many offices to become chancellor (munha sijung), served as chief state councillor (docheomui jeongseung), and was enfeoffed as Lord of Gyerim (Gyerim Buwongun).
At the Man'gwondang, the library that King Chungseon established in the Yuan capital of Yanjing, he associated with Yuan scholars such as Zhao Mengfu and deeply absorbed Neo-Confucianism, which he transmitted to Goryeo, laying the foundation for the scholarly lineage of the emerging literati (sinjin sadaebu) that led to Yi Saek.
Skilled in both literature and history, he left the collected works Ikjae nan'go and the miscellany Yeogong paeseol, and also took part in compiling the national history.
He is the founding ancestor of the Ikjae line of the Gyeongju Yi clan, and his daughter was Lady Yi, the Hyebi consort of King Gongmin.