For our money, The Dark Knight is the greatest comic-book movie ever made.

You'd be hard pressed to find another film of the same genre that comes anywhere close to the sheer perfection that was The Dark Knight. As well as being Heath Ledger's greatest role in his sadly short career, it's easily up there with Christian Bale's greatest performances.

It's been analysed to within an inch of its life - it's all about game theory, apparently - and there's been endless fan theories surrounding it, but what happened on set? Why did Heath Ledger do his own makeup? Who was originally lined up to play Harvey Dent?

We've answered all these and more below. Check it out!