When Ben Affleck was first announced as Bruce Wayne in Batman v Superman: Dawn of Justice last year, legions of fans took to the Internet to express their hatred for the casting. While he may have been the last choice for the fans, producer Charles Roven, who also produced last year's Man of Steel, revealed Ben Affleck was their first and only choice to play this new version of The Dark Knight.

"He was the first guy we went to. That's who we wanted. We knew that we wanted a very mature Batman, because we wanted to juxtapose him with this very young Superman. So we wanted a guy who was tougher, rugged, who had signs of life, who had lived a hard life, and we wanted the guy to have chops, for sure. So when we went down that list, there just weren't a tremendous number of guys who could carry that."

The producer added that the actor's height, at 6 feet 4 inches tall, was another important factor in his casting, since they wanted Henry Cavill's Superman to literally have to look up to Batman.

""We also wanted a guy with big stature. Ben is 6' 4". Henry [Cavill] is 6' 1". We wanted Batman to tower over Superman. Not hugely, not like a basketball player. Superman needed to 'look up' to Batman. We wanted that dynamic, and Ben could do that, easily."

Charles Roven added that it helped Ben Affleck also has a strong relationship with Warner Bros., where he directed his Best Picture winner Argo.

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"We have a very strong relationship with Warner Bros. obviously; all of the DC comics are at Warner Bros. Ben had literally just won the Oscar for Argo, which was a Warner Bros. movie, so it wasn't like it was difficult to reach him."

When asked if Ben Affleck showed any hesitation about taking on the role, Charles Roven had this to say.

"No, I wouldn't say he hesitated. I think that what he did do was that he made sure that he understood what (director) Zack (Snyder) was looking for, to know exactly how Zack planned on treating this Bruce Wayne that was going to make him completely different even though he was still Bruce Wayne, still Batman."

The producer also teased that this version of Batman is "extremely rough" when he's in the Batman suit, but he is also a "social animal" in public as Bruce Wayne.

"He's much more of a social animal in the Bruce Wayne incarnation, but he's also an extremely rough guy in the Batman incarnation - very, very, very rough."

When asked about how involved executive producers Christopher Nolan and Emma Thomas are in the production, Charles Roven admitted they are more focused on their upcoming sci-fi thriller Interstellar, but he has been involved in certain aspects of production, including the casting of Ben Affleck as Batman.

"[Nolan] is an executive producer on the movie, as is Emma Thomas, his wife. And I would say that he's much more focused on the movie Interstellar, writing, directing. He co-wrote it with his brother. ... They were off doing that movie. (He was) certainly involved in different stages. I would say he has an advisory capacity."

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