Back in 1990, Irish/German actor Michael Fassbender’s last name was a rich gift to the schoolboys of St. Brendan’s College (Colaiste Bhreanainn in Irish) in Killarney, Co. Kerry.

For the entire first year they teased the life out of Fassbender over it. It was the “bender” part, local slang for “gay.” That’s not a word that 13-year-old boys can be readily trusted with, even in an upscale school for middle class Irish boys that originally opened in the 1860s.

The unmistakably heterosexual actor is reportedly dating his "Shame" co-star Nicole Beharie, but teenage boys can’t resist an easy target and for 12 months back in the '90s they let him have it, thinking up every way to rhyme his name that they could, until they got to know him and decided they liked him, which made them stop.

Born in Germany and raised in Killarney, where his parents have run a successful restaurant since 1993, Fassbender was always going to be a little different to the other kids. For one thing it was said that he speaks fluent German.

“I put fluent German on my CV but that’s a little bit of a white lie,” Fassbender tells the Irish Voice with a laugh. But even the legend was enough to make the local tongues wag.

“I guess I did feel somewhat like an outsider just because Fassbender sticks out among the Fitzgeralds and O’Sullivans and O’Connors and whatnot,” he confesses. “But in the area I grew up there was kind a lot of German immigrants there just because of the hotel and factory that had been set up there in Kerry.

“So there was a kind of community. And it’s funny because all -- well, two of my very close friends from school -- one of them is Italian Canadian and the other’s half Irish and American from San Diego. So I guess we all kind of stuck together a little bit.

“But then I went to London and I felt more Irish. It really sort of depends on when you leave. I think then you realize what your roots are when you go away from it.”

Fassbender, 36, is away from his Kerry roots more often than ever now, thanks to becoming one of the most sought after lead male actors of his generation. Sharing the screen alongside Brad Pitt and Benedict Cumberbatch this week, he has emerged as a star in his own right.

In "12 Years a Slave," which opens on Friday, Fassbender delivers an Oscar worthy performance in another remarkable film by director Steve McQueen. (Fassbender has spoken of his hurt at being passed over by the Academy for his work in "Shame," an inexplicable snub that they cannot possibly replicate this time and hope to call themselves judges).

Fassbender’s performance in the new film is flawless, echoing the best work of the film’s lead Chiwetel Ejiofor, who gives one of the greatest performances committed to film in his role as Solomon Northup, a man kidnapped and sold into slavery in Louisiana in the 1830s. With a little luck and a lot of common sense, both men should be holding golden statues at the Oscars next year.

McQueen was already preparing to direct "12 Years a Slave" when Fassbender was doing the publicity rounds for "Shame," he says.

“He told me when we were on the 'Shame' press junket that the next film he wanted to make was about slavery and I thought, ‘Of course, that makes sense.’

“And then I got the script several months later and I read it. At that point he didn’t say, ‘I want you to play Edwin Epps’ (the brutal Louisiana slave owner) but when I read it I was hoping he would offer me that role. I called him up immediately after I read the script and said I’d do anything to work on this, even if it’s only one or two days work, I want to be involved.”

The role is one of the most challenging of Fassbender’s career because the character treats black people worse than livestock. He doesn’t believe in their humanity at all. He thinks black people are a subhuman species that cannot think or feel like he does. He’s also a rapist who quotes the Bible at everyone he thinks is inferior to him.

That’s not the kind of role that your typical Hollywood star would jump at, always conscious of their public image, but Fassbender didn’t hesitate because he understood the power of the story the film was telling.

“I was glad to take on the responsibility of playing him for sure, just because I thought the story was so beautiful. I just think that’s an important thing that Steve manages to do in all of his films to date,” says Fassbender.

“From the start we start seeing the world through Solomon’s eyes. It’s almost like as an audience we become Solomon. Full credit to Chiwetel for doing that.

“So many times when we go to see a film now there’s the audience and then there’s what is happening on screen. There’s that comfortable divide. But with Steve pretty quickly the audience is transported into the world and they’re partaking in it and that’s a difficult thing to do.”

"12 Years a Slave" works because McQueen approaches the dynamite subject and the characters without judgment, Fassbender says.

“It’s not like the classic scenario between master and slave. It’s more complex than that. It’s about the complexity of that relationship and the complexity of slavery,” Fassbender says.

“We see Solomon go from a logging farm to a cotton farm to a sugarcane farm, so we see the economics of slavery of the time and how intrinsic slavery was to the economy of the south.

“It doesn’t just become a black and white scenario of the bad slave owner and the slaves, you know? We see Mistress Shaw (played by Alfre Woodward) lives like the lady of the house. We see how scenarios like that unfold. She’s a black woman (apparently colluding in the oppression of other black people).

“It doesn’t become a judgmental piece; it just becomes a thing where we are transported into that world. It becomes a more real world.”

Fassbender knew he was in good hands when McQueen approached his character, one of the most odious in the film, with sympathy for his point of view.

“It’s that kind of understanding that he has of the characters that makes for his dispassionate directing,” Fassbender says.

Fans of Fassbender’s unforgettable work on Ridley Scott’s "Prometheus" (I raise my hand here too) will be delighted to hear that there’s talk of a sequel with himself and Noomi Rapace reprising their roles. Since his character David was the most compelling in the film this is good news, but

Fassbender says he hasn’t heard final confirmation of the project yet.

“A lot of people are asking me about that recently. I’m not sure, no one has told me anything about it,” Fassbender offers.

“I would love to do the robot again. Hopefully Noomi (who plays Elizabeth Shaw in "Prometheus") stitches my head back on my body!”

One of the most anticipated films is the "X-Men: Days Of Future Past" follow up, with Fassbender reprising the role of Magneto. The film’s director Bryan Singer teased a picture of the Irish actor in a wide brimmed hat and shades (easily one of the coolest pictures of the year), but what is going on in that scene?

“You have to wait and see,” Fassbender laughs. “That was a collaborative thing with the wardrobe and the director. It was a little top of the hat to Ian McKellan because we’ve seen him wear it.

“We were trying to use what was available at the time (which is the 1970s) and keep him disguised, although the look would kind of draw attention to yourself so it’s kind of a double edged sword.”  

Meanwhile, "12 Years a Slave" is about to open and it seems certain to become a cultural and cinematic milestone when it does, thanks to its explosive subject and unflinching treatment.

Perhaps for that reason Fassbender and McQueen have been discussing toning it down for their next collaboration, whenever that occurs.

“I think we’re trying to do something a little lighter next time. We have been talking about a musical. Wait and see,” he says again.