CP3S said:

We've known a lot of that stuff long before the prequels came out. But what was the source for it? For years I had my Return of the Jedi Luke Skywalker action figure playing the role of Anakin fighting my Obi-Wan figure on sofa cushions that served as the cliff of a volcano. I've known this was Anakin's fate and what made him Darth Vader for as long as I can remember, since before I had any exposure to the EU, but why did I know this? Wasn't it in the Return of the Jedi novelization or something?

Not sure, I think it might have been said by Lucas before ESB, I think I remember when you saw the back of Vader's scarred head in ESB, everyone had heard how that happened........hmmmm