Battlefield Heroes is a 2011 South Korean war comedy film directed by Lee Joon-ik. The film is a sequel to the 2003 film Once Upon a Time in a Battlefield and stars Jung Jin-young, Lee Moon-sik and Ryu Seung-ryong. The film is set in 668 and chronicles the war between the southern Korean state of Silla against the larger northern Korean state of Goguryeo. The film's box office returns were lower than expected in South Korea, which prompted Lee Joon-ik to announce his retirement shortly after the film's release. The film has been shown at the New York Asian Film Festival and Fantasia Festival.