Once Upon a Time in a Battlefield (Korean: 황산벌; RR: Hwangsanbul) is a 2003 South Korean war comedy film directed by Lee Joon-ik. Its plot is about the Battle of Hwangsanbeol between Baekje and Silla in the 7th century. The film was the 8th most attended film of 2003 with 2,835,000 tickets sold nationwide. Its popularity has spawned a sequel, titled Battlefield Heroes, which debuted in 2011, and takes place in the subsequent Silla-Tang invasion of Goguryeo.