Arrival of Neo-Confucianism
Under King Chungnyeol, An Hyang brought Neo-Confucianism from the Yuan; through Yi Je-hyeon and Yi Saek it became the creed of new scholar-officials such as Jeong Mong-ju and Jeong Do-jeon.

Yi Bul-hae · Public domain · Source
An Hyang copied Zhu Xi’s works in the Yuan and introduced them; Baek I-jeong studied in the Yuan and taught Yi Je-hyeon and others. At the Mangwondang library that King Chungseon founded in Dadu (1314), Yi Je-hyeon befriended Yuan scholars. Under King Gongmin, Yi Saek led the Seonggyungwan and trained Jeong Mong-ju, Jeong Do-jeon and others.
Goryeo Neo-Confucianism stressed practice in daily life, spreading the Elementary Learning and Zhu Xi’s Family Rites, and criticized Buddhist abuses. It became the reform ideology of the new scholar-officials against the magnates and the Buddhist establishment.