Yi An-sa (1204 – 3 March 1274) was a Goryeo nobleman who would become the great-great-grandfather of Yi Seonggye, founder of the Joseon Dynasty.
On 28 July 1392, when Taejo made a new dynasty, he was granted the royal title King Mok (). After his death in 1274, he was buried in Deokneung, Neung-ri, Gapyeong-myeon, Sinhung-gun, South Hamgyong Province, North Korea and given the temple name Mokjo () by his great-great-great-grandson, King Taejong on 22 April 1411 along with his posthumous name.
Family Father: Yi Yang-mu (이양무; 1186–1231) Grandfather: Yi Rin (; 1150–?) Grandmother: Lady Mun of the Nampyeong Mun clan (; 1149–?); third daughter of Mun Geuk-gyeom (; 1122–1189). Mother: Lady Yi of the Samcheok Yi clan (; 1182–?) Grandfather: Yi Gang-je (; 1161–1260) Older brother: Yi An-in (이안인; 1202–?) Younger brother: Yi Yeong-pil (; 1205–?) Younger brother: Yi Yeong-mil (; 1206–?) Younger brother: Yi Yeong-seup (; 1208–?) Wife: Queen Hyogong of the Pyeonchang Yi clan (; 1207–?) First son: Yi Eo-seong, Grand Prince Ancheon (이어선 안천대군; 1230–1274) Second son: Yi Jin, Grand Prince Anwon (; 1232–?) Third son: Yi Jeong, Grand Prince Anpung (; 1234–?) Fourth son: Yi Haeng-ni (; 1236–?) Fifth son: Yi Mae-bul, Grand Prince Anchang (; 1238–?) Sixth son: Yi Gu-su, Grand Prince Anheung (; 1240–?)
References
목조 on the Encyclopedia of Korean Culture .