and early 1990s, including the ability to create computer-generated imagery (CGI), inspired Lucas to consider that it might be possible to revisit his saga. In 1989, Lucas stated that the prequels would be "unbelievably expensive". In 1992, he acknowledged that he had plans to create the prequel trilogy. A theatrical rerelease of the original trilogy in 1997 "updated" the 20-year-old films with the style of CGI envisioned for the new trilogy. Episode I: The Phantom Menace was released on May 19, 1999, and Episode II: Attack of the Clones on May 16, 2002. Episode III: Revenge of the Sith, the first film in the franchise, was released on May 19, 2005. The first two movies were met with mixed reviews, with the third being received somewhat more positively. The trilogy begins 32 years before Episode IV and follows the Jedi training of Anakin Skywalker, Luke's father, and his eventual fall from grace and transformation into the Sith lord Darth Vader, as well as the corruption of the Galactic Republic and rise of the Empire led by Darth Sidious. Together with the original trilogy, Lucas has collectively referred to the first six episodic films of the franchise as "the tragedy of Darth Vader". Sequel trilogy Prior to releasing the original film, and made possible by its success, Lucas planned "three trilogies of nine films". However, he announced to Time in 1978 that he planned "10 sequels". He confirmed that he had outlined the prequels and sequels in 1981. At various stages of development, the sequel trilogy was to focus on the rebuilding of the Republic, the return of Luke in a role similar to that of Obi-Wan Kenobi in the original trilogy, Luke's sister (not yet determined to be Leia), Han, Leia, R2-D2 and C-3PO. However, after beginning work on the prequel trilogy, Lucas insisted that Star Wars was meant to be a six-part series and that there would be no sequel trilogy. Lucas decided to leave the franchise in the hands of other filmmakers, announcing in January 2012 that he would make no more Star Wars films. That October, the Walt Disney Company agreed to buy Lucasfilm and announced that Episode VII would be released in 2015. The co-chairman of Lucasfilm, Kathleen Kennedy, became president and served as executive producer of new Star Wars feature films. Lucas provided Kennedy his story treatments for the sequels during the 2012 sale, but