Nakcheon was born in Hanseong. He is the son of Yi Chae and Lady Ryu of Jinju. His original family is descended from Prince Kyeongchang, the ninth illegitimate son of 14th King Seonjo of Joseon. In 1773, he was adopted by Prince Yeonryeong, illegitimate son of 19th King Sukjong of Joseon.