Jeong Do-jeon
Jung Do-jun (korean:정도전, hanja:鄭道傳, 1337(?) or 1342(?) – 1398), also known by the pen name Sambong(삼봉), was the most powerful medieval Korean aristocrat and politician in the early Joseon dynasty. He was also an influential Neo-Confucian ideologue and was the closest supporter and advisor to King Taejo, who founded the Joseon dynasty. After Taejo became the first king of Joseon, he left all state affairs to Jeong Dojeon, making him the most powerful and influential man who shaped 500-year-long Joseon dynasty by laying down its idealogical, institutional, and legal foundations. It is even said by some historians that Jeong Dojeon founded Joseon through Taejo, rather than the other way around.
Read more about Jeong Do-jeon: Work Book, Intellectual Activity, Political Thought