Conquest of the Planet of the Apes is a 1972 American science fiction film directed by J. Lee Thompson and written by Paul Dehn. The film is the sequel to Escape from the Planet of the Apes (1971) and the fourth installment in the original Planet of the Apes film series. It stars Roddy McDowall, Don Murray, Ricardo Montalbán, Natalie Trundy, and Hari Rhodes. In the film, set in a world that has embraced ape slavery, Caesar (McDowall), the son of the late simians Cornelius and Zira, surfaces out of hiding from the authorities and prepares for a rebellion against humanity.