Jack O'Connell breaks through in Unbroken

Based on the book by Laura Hillenbrand, Unbroken has a screenplay by Joel and Ethan Coen

Ten years ago, Jack O'Connell was sleeping on park benches to attend auditions. Now he's the talk of Hollywood for his lead role in Angelina Jolie's World War Two epic, Unbroken.

"I kind of assumed that it would be a longer road than this one," admits Derby-born actor O'Connell. "Try telling me that at the age of 15 when I was sleeping rough in parks, because I couldn't afford to accommodate myself."

The ex-Skins actor is in a top London hotel to discuss Unbroken and the role that looks set to propel him to global attention.

And what a role it is. O'Connell plays Louis Zamperini - an American athlete who competed at the 1936 Berlin Olympics before becoming a pilot during World War Two.

Shot down over the Pacific, he survived 47 days adrift on a raft before being captured by the Japanese and endured two years of mental and physical torture in prisoner-of-war camps.

Angelina Jolie has said Zamperini, who died in July, was 'full of love and life'

Zamperini competed in the Olympic Games in Berlin in 1936 in front of Adolf Hitler

Jack O'Connell in Unbroken, which is released in UK cinemas on 26 December

O'Connell got to meet Zamperini twice in Los Angeles before he started shooting. Their first encounter, which was being filmed, he found "awkward and intrusive" so he asked to meet Zamperini again alone.

"He was kind enough to agree, he brought me into his family home again, and I could just interact and engage with him. He got his scrap book out and I went through his highlights. He had an incredible sense of humour."

One item of "memorabilia" Zamperini showed O'Connell was a Nazi flag he had stolen from the Berlin Olympics, where he had also received a handshake from Adolf Hitler. "He nearly got himself shot doing that," O'Connell notes.

"He never considered himself superhuman, or extraordinary. He just presented himself as a normal human being that had endured a lot."

The war veteran died in July 2014, aged 97, after the film had wrapped. O'Connell had met him for a third time by then. "It was quite celebratory, but of course I had no idea at that time that it would be our final meeting, someone like Louis you just assume is going to be around forever."

At the age of 24, O'Connell has made his name in a series of gritty roles in both TV and film.

He made his movie debut as teenager Pukey in 2006's This is England, went on to appear as a villain in horror thriller Eden Lake, and opposite Michael Caine in Harry Brown. He's best known on TV for his role as James Cook in the E4 series Skins.

He received enthusiastic reviews for prison drama Starred Up, which tells the story of a young offender thrown into an adult prison for being too violent.

Jack O'Connell made his movie debut in 2006's This Is England

This autumn he was also seen in '71, the debut feature film by French director Yann Demange, as a teenage soldier in Northern Ireland accidentally abandoned by his unit following a riot on the streets of Belfast.

"It's been like an apprenticeship," he reflects. "Lessons were learnt back then and I'm going to benefit from it now, and I'm going to continue to learn, ideally, because it's an art form, and a vast one at that, and I'm just a drop in the ocean."

But O'Connell hopes his higher profile will help create opportunities for people who, as he says, are "from similar backgrounds" to himself.

His long-term ambition is to set up his own production company "so I can, from the bottom up, create roles, create projects, create jobs and opportunities".

With Unbroken putting O'Connell into the global spotlight, his park bench days are far behind him.

Future film appearances include 17th Century romance Tulip Fever, alongside Alicia Vikander and Christoph Waltz; and Terry Gilliam's fantasy epic The Man Who Killed Don Quixote.

But he's not forgotten roughing it for those early auditions and his first professional gig as an actor in BBC daytime drama Doctors in 2005.

"I had people championing me as a kid, and that made me feel like I wasn't wasting my time.

"It's quite a risky business that I've got myself into," he adds. "I'm just very thankful that it's paying off at the minute."

Unbroken is out in the UK on 26 December.