4. He was the first actor to win an Oscar for playing a villain
The Dark Knight was nominated for eight awards during the 81st Academy Awards. Ledger won the Best Supporting Actor for his role as the Joker, being the first and only to win in any of the categories for a movie like that – superhero movies don’t tend to be something that the Academy looks for, but Heath was the exception.
5. He was inspired by Clockwork Orange
While researching for his portrayal of the Joker, Ledger gained huge inspiration from the 1971 classic Clockwork Orange. He looked at the main character Alex De Large, played by Malcom McDowell – his portrayal of his character was astounding at that time. This is how he really developed the strange mannerisms that the Joker possessed.
6. ‘The Joker Journal’
You’ve probably heard about this one before. While on set, Ledger was often seen carrying around a diary.
It was revealed that within this journal, Ledger wrote as if he was the Joker – there was a list. A pretty messed up list. It contained ramblings of a mad man, things that the Joker might find funny – geniuses that had brain damage, sombreros, blind babies.
This is some pretty strong indication that Ledger may have been a little bit mad himself. It just goes way beyond the protocol of somebody trying to get in character for a movie.