How did he go off the deep end? Like, how did he go from respected historian to Holocaust denier?
Ron Rosenbaum, in “Explaining Hitler” (a book about the various theories of “why was Hitler Hitler”), says that colleagues of Irving told him that after some of Irving’s earlier (still controversial, but not Holocaust denial) works were published, and received decently, he was put in touch with some of Hitler’s surviving inner circle. Apparently they wanted to share their views of Hitler the person with someone they viewed as fair minded, and Irving’s colleagues think that being brought into their trust broke him.
Which makes sense - he was controversial back home, but now these people are welcoming him and giving him secret knowledge? They must be on to something! “They like me! That means they’re good people! They liked Hitler, which means good people like Hitler!”
