"This one is a little tougher, and I think children, young children especially, should be warned that this is not your average Star Wars. It's a lot darker. There's a lot more scary stuff in it. It's brutal in places, and they should be aware of that. And at least if it does come out to be a PG-13, the parents are warned to be careful of bringing tiny little kids, like five and six years old, because it might be too much. Know your kids. I have three kids—they’re all grown up now—but when they were six, I knew what I could take them to and couldn't. People think Star Wars is extremely innocent, although we do cut a lot of people in half and cut off a lot of arms."
January 1, 1970
https://en.wikiquote.org/wiki/Star_Wars%3A_Episode_III_%E2%80%93_Revenge_of_the_Sith