Yi Cha-hŭng (born 1305), posthumously known as Grand Prince Wanchang was a late Goryeo periods second rank official (좌윤; 左尹) who became part of the early Joseon royal family member as the first and oldest son of Yi Ch'un, making him uncle to Yi Seonggye, its founder.
He studied in Yeokdong (역동; 易東) as one of U Tak (우탁; 禹倬)'s student. In Yuan dynasty, Yi served as one of the government official (천호; 千戶) in there. After his nephew, Yi Seong-gye (이성계) established the new dynasty, Yi Cha-hŭng served his nephew as Taejo's military officer (병조판서; 兵曹判書) and on 9 March 1871, Yi was given Posthumous name Jeonggan (정간; 貞簡). In 1872, Emperor Gojong of Korea gave him a posthumous name as Grand Prince Wanchang (완창대군; 完昌大君) and was enshrined in Yeongjongjeonggyeong (영종정경; 領宗正卿) alongside his parents. Their tomb located at Gwiju-dong, Hamheung.