Episode IV: A New Hope (1977)
* Written by: George Lucas
* Directed by: George Lucas
Episode V: The Empire Strikes Back (1980)
* Written by: Leigh Brackett and Lawrence Kasdan (story by George Lucas)
* Directed by: Irvin Kershner
Episode VI: Return of the Jedi (1983)
* Written by: Lawrence Kasdan and George Lucas
* Directed by: Richard Marquand
Episode I: The Phantom Menace (1999)
* Written by: George Lucas
* Directed by: George Lucas
Episode II: Attack of the Clones (2002)
* Written by: George Lucas
* Directed by: George Lucas
Episode III: Revenge of the Sith (2005)
* Written by: George Lucas
* Directed by: George Lucas
As you can see, while George Lucas was heavily involved in all of the films, he did not direct all of them. He directed four films, while Irvin Kershner and Richard Marquand directed one each.