"Namhansanseong" is adapted from the best-selling Korean historical novel of the same name published in 2007. Set against the backdrop of the Bingzi Rebellion in 1636, the 14th year of King Injo's reign, the film tells the story of the Later Jin (Qing) attacking Joseon. King Injong (Park Hae-il) and his ministers, including Choi Myeong-gil (Lee Byung-hun) and Kim Sang-hun (Kim Yoon-seok), were forced to the Namhansanseong Fortress. For 47 days, they were isolated from the outside world and were in a dilemma. Under the powerful Qing offensive, Choi Myeong-gil advocated peace for the lives of the people; Kim Sang-hun advocated continuing to fight with the Later Jin (Qing).