The Superman film series consists of five superhero films based on the DC Comics character of the same name. The films contain storylines such as Superman's origin story, growing up in Smallville, fighting Kryptonian supervillains and Lex Luthor, romancing with Lois Lane, and returning to Earth after a long visit to Krypton. Warner Bros. has served as main distributor of all films. Ilya and Alexander Salkind and Pierre Spengler had purchased the Superman film rights in 1973. After numerous scripts, Richard Donner was hired to direct the film, filming Superman and Superman II simultaneously. Donner had already shot 80% of Superman II before it was decided to finish shooting the first film. Richard Lester finished with II and returned for Superman III. Upon gaining the rights for Superman, Alexander Salkind and his son, Ilya Salkind, had also purchased the rights to the character of Supergirl, which resullted in the 1984 spin off Supergirl. Cannon Films acquired the film rights to Superman, resulting in Superman IV: The Quest for Peace. With over 15 years of development for a fifth Superman film, Superman Returns was released, directed by Bryan Singer. Superman II: The Richard Donner Cut was released the same year. Critics have given positive reviews for Superman, Superman II, Superman II: The Richard Donner Cut and Superman Returns, while Superman III, Supergirl and Superman IV have been met with negative feedback.