John Boyne’s novel “The Boy in the Striped Pajamas” is a Holocaust fable about Bruno, the eight-year old son of the commandant of a Nazi death camp, who forges a forbidden friendship with a boy in the camp. In a recent Dallas interview, he recalled that writing the book had been remarkably easy. “When I had the idea of these two boys sitting at the fence talking to each other, it just presented itself to me as a story that I knew how to tell,” he said. “When I started with the opening pages and got into that tone of voice, fable-like, with a third-person narrator although it’s a bit of a first because everything is seen through the boy’s eyes except the last three pages, I just felt I knew how to write it, and that I could tell this story in an interesting, unusual, fresh way. All of the research I’d done over the years and all the reading I’d done fed into the story, but I just knew the morning I started writing it exactly what to do. I’d never felt that way about a book before.”

Written with young readers in mind but soon taken up by adults, the novel was an immediate success when it was published in 2006, winning numerous awards. But Boyne doubted it would ever be filmed. “No—definitely not,” he said. “Even after [director] Mark [Herman] had bought the rights, even after I was reading drafts of the screenplay, I still thought it was a long shot. I didn’t really think it was going to happen.”

But Boyne hadn’t reckoned with the determination of Herman, who accompanied him to Dallas. Herman, best known for “Little Voice” and “Brassed Off,” was attracted to the book as soon as he read it and shepherded it to the screen.

“I’d just spent a few years doing a romantic comedy,” Herman explained, “and I was keen to spend the next few years on something a bit more weighty. I sat around for a few months trying to think of some ideas, but nothing ever arrived. The only thing that did arrive was John’s book. John and I share the same agency, so I got an early look, even before it was published. And it’s just his unique angle, I think, more than anything else—it’s not just another Holocaust story, or another one through the eyes of a child, but actually through the eyes of a German child—that I thought was really intriguing. And I thought this was a chance for me to be my own boss for a short while, to have my own control over the screenplay, so I bought the rights myself and spent the next six months writing the screenplay, without having notes from on high, as usually happens.”

But Herman brought Boyne into the preparation early on, which the novelist found especially gratifying. “It’s rare for the author of a novel to be such a part of the process, to be so involved and so welcomed into it,” he said. “We first met in the summer of 2005, and during all that time never had a cross word, never had a disagreement. And I always felt that Mark and [producer] David Heyman always respected the role of the novelist and thought that I had something I could bring to the project.”

After honing the screenplay, Herman took it to Miramax. “I thought that they’d probably be the only studio brave enough to go down this road,” he said. “And that’s what happened. They read the screenplay and felt this was an opportunity to make something very special. They know it’s a marketing challenge, but I think they felt, like we’re realizing now, that the word of mouth on the film would be very, very strong. It’s a big hit in Europe on the basis of word of mouth more than anything else.”

The film was shot in Hungary with a local crew who committed themselves to the project. “The rumor in Budapest is that crew members often jump from one project to another” for monetary reasons, Herman said. “But we didn’t lose a single member because they were very passionate about the project.”

And it attracted a stellar cast, including David Thewlis and Vera Farmiga as Bruno’s parents. But the picture depends enormously on the two boys, especially Asa Butterfield, who’d had only tiny parts in two films before taking on the demanding part of Bruno, who appears in almost every scene. “We saw hundreds and hundreds of kids, and oddly enough Asa was on the first tape I saw,” Herman recalled. “And it’s a bit like when you’re buying a new house, and the first one you see is fantastic, but there must be something better coming along. But that’s never the case. We kept on looking, but we kept bringing Asa in for auditions, and he was getting better and better all the time. He looked so good on the video screen that I knew on the big screen he was going to be something very special. And that’s proved to be the case.”

Directing Butterfield and Jack Scanlon, who plays the Jewish prisoner Shmuel, was a challenge because of restrictions on the number of hours they could be on set, Herman said. But both proved very dedicated.

“I learned the difference between being a film director and being a parent,” Herman said, “is that if you’re a film director and you ask your kids to do something, they actually do it.”