Ben Mendelsohn is riding a late-career wave of international success, and it's built on being menacing.

After gaining international attention for his role as Pope — the most violent and terrifying member of a crime family — in the film Animal Kingdom, Mendelsohn has developed a reputation for playing unpredictable and dangerous men.

He followed that with the unsettling Danny Rayburn in the television series Bloodline.

And now, in the just-released film, Una, he plays possibly his most despicable and unlikeable character yet.

"Una is in a sort of a category of its own for, for difficult and unpleasant situations to be playing out," Mendelsohn told 7.30.

"The guy is a paedophile and he is discovered in his 'new life' by his victim.

"Yeah, it's messy work."

Being menacing

Sorry, this video has expired Ben Mendelsohn talks about being menacing on-screen

Mendelsohn's on-screen persona is a million miles from the real Ben Mendelsohn, who, in person, is engaging and likeable.

He puts his ability to be intimidating on screen down to his Australian upbringing.

"It's in the lexicon of Australian language. It's just [part] of Australian non-verbal language," he said.

"I think it's something you learn growing up here.

"If you grew up in the outer suburbs or you spent time there, you know this stuff.

"You know it walking past guys on the street, it's something you've got to learn how to do to kind of exist. So it's just taking that."

Not working and international success

Sorry, this video has expired Ben Mendelsohn talks about late-career international success

After a successful career in Australia when he was a young actor, Mendelsohn had three years in the early 2000s where he didn't work.

That, he said, has made his recent international success easier to deal with.

"It [the time out] was actually a really pleasant period in a lot of ways, but it's made all of this stuff that comes afterwards particularly kind of very sweet, you know," he said

"It's not typical, I guess, to be finding this sort of success in one's middle age. So it's pretty cool."

But he believes that initial success "mucks you up", no matter when it happens.

"I have never seen it hit anyone, anyone, where it hasn't altered them for a period of time, which is typically like six months to three years," he said.

"And you're kind of gone, in one way or another, in that period."

Star Wars

Sorry, this video has expired Ben Mendelsohn on starring in the latest Star Wars film, Rogue One.

One of the additional perks of that success was that he landed a role as Orson Krennic, a Lieutenant Commander to Darth Vader, in the latest Star Wars movie, Rogue One.

"The first time you walk on, you know, and you see storm troopers for real, it's pretty awesome," he confessed.

"And then if you have the good fortune to meet Darth. That's a whole other world of Star Wars!"

As a kid who grew up watching Stars Wars films, did he ever dream he'd be in one? And if he could, what would he say to his younger self about it?

"I thought about this one a lot. I would have just said to little Ben, 'Don't worry, one day you'll be in Star Wars'," he said.

"There would have been a lot of things, a lot of worries and angst and stuff that, you know, if I could have told him, 'Don't worry, mate. One day you'll be in Star Wars', it would have settled things a lot."

Homesickness

Sorry, this video has expired Ben Mendelsohn on what he gets homesick for.

Apart from a brief visit a couple of years ago, Mendelsohn has been living and working overseas for seven years.

And, despite all the success, there are some things he still misses.

"I get very, very homesick for particular things," he admitted.

"I get Vegemite homesickness. I get meat pie homesickness. I get chocolate milkshake homesickness. I get coffee homesickness."

"And I do miss the people. Yeah, I miss the Australian way of talking rot."