Harvey Dent was arguably the most significant actor Harvey Dent was arguably the most important character in The Dark Knight,
but Christopher Nolan's original concept for Two-Face would lead to a totally different Dark Knight trilogy.
After reviving this Batman brand with Batman Begins featuring only the villains that have never been featured in any Batman film,
Nolan brought two major characters into The Dark Knight who had previously appeared at the cinema in the form of The Joker along with Harvey Dent.
But, Christopher Nolan and David S. Goyer's plans for their Batman films started with the introduction of Harvey Dent much earlier than the character was introduced.
Although Harvey Dent has been part of the most notable Batman comic book tales like The Long Halloween and The Dark Knight Returns, however, the Batman movies were yet to fully portray the character.
Harvey Dent had a very tiny part on screen in Batman (1989) as well as the plot Tim Burton had set up for Billy Dee Williams' Two-Face did not get created.
Two-Face was reintroduced with Batman Forever, played by Tommy Lee Jones,
but the character was more like the character of Jack Nicholson's Joker than the previous Harvey Dent iteration.