George Lucas says that Darth Vader was the main character in Star Wars, not Mark Hamill's Luke Skywalker.
Star Wars is one of the most successful franchises ever made, way more successful than the original creator, George Lucas, ever intended it to be. So, when Lucas came out and said that Mark Hamill as Luke Skywalker was never supposed to be the lead in Star Wars and that he’d planned for Darth Vader to be the lead in the first six films (via SlashFilm), many fans of the space fantasy franchise were pretty surprised, and honestly, kind of skeptical.
When the first Star Wars movie came out, George Lucas took off on a Hawaiin vacation with his pal Steven Speilberg to avoid the premiere of A New Hope, which he was convinced was going to fail. So, when Lucas said in an interview many years later that he’d planned the whole series out in advance, people were suspicious. They were even more doubtful when Lucas said that Mark Hamill was never the lead of the original movies and that Darth Vader was, in fact, the main character, with many stumped at how that worked out, considering that the majority of the movies are largely from Luke’s perspective.
In the first movie (Episode IV), George Lucas wrote the film to be about Mark Hamill’s Luke Skywalker, following a perfect Hero’s Journey format. While Darth Vader is a pretty bad dude in the film, he’s not even the main antagonist, with the evil empire being represented by Grand Moff Tarkin (Peter Cushing). When looking back at the original films, the idea for Vader to be the main character didn’t seem to pop into Lucas’ head until he was writing the sequel to A New Hope after Star Wars unexpectedly became a major hit.
In The Empire Strikes Back, Vader’s role suddenly expands from him being the Empire’s lackey to Vader now being the right-hand man to the Emperor as well as Luke’s (Mark Hamill) dad (something that wasn’t added in until the second revision of the script, by the way). However, even though Vader’s story gets expanded as he goes through his redemption arc in Episode VI and we get his backstory in Episodes I-III, George Lucas never makes it clear that Vader should be the main character, even though Lucas himself certainly seemed to think it was obvious.
“Originally, people thought it was all about Luke. The early films are about Luke redeeming his father, so Luke’s the focus. But it’s also about Princess Leia and her struggle to reestablish the Republic, which is what her mother was doing. So it’s really about mothers and daughters and fathers and sons.”
Maybe in George Lucas’ mind, it’s pretty clear that the Star Wars franchise is about family bonding, but to the majority of audience members, Mark Hamill was always the obvious lead. When looking at the original films through a microscope, Luke is never very successful at redeeming his father. Vader was a terrible guy who killed millions of people (including blowing up a whole populated planet and slicing and dicing a room full of innocent children), and his redemption arc at the end of Return of the Jedi is pretty weak, considering that the Rebels probably would have won the war even if Vader hadn’t stepped in to have it out with the Emperor.
Suffice it to say, it doesn’t balance out.
What likely happened was that after Star Wars blew up into a way more popular series than George Lucas ever expected it to be, he decided to recontextualize his material, adding in story details that weren’t there to begin with to make it all seem grander and more complicated. So, while Lucas might no longer believe that Mark Hamill was the lead actor in the movies, it still makes a lot more sense than Vader being the main character. At least for the first three films.