As a schoolboy, growing up near Bradford, Matthew Lewis would lose himself in his collection of Harry Potter books.

JK Rowling’s engaging stories, about the adventures of a boy wizard and his chums, sparked the budding actor’s vivid imagination and he saw himself in the thick of the action at Hogwarts.

Aged 11, Matthew announced to his mum: “If they make a film of the Harry Potter books, can I go for an audition?”

That same year, Matthew landed the role of a lifetime. Now 22, he has played Harry’s loyal friend Neville Longbottom in every one of the blockbuster movies based on Rowling’s series of seven children’s books, now a global sensation.

Now one of the nation’s most recognisable young actors, Matthew has grown up with Neville.

Just as Neville has gone from being a geeky, bullied little boy into a brave warrior, fighting Voldemort and his evil forces, Matthew has grown from a cute, tousle-haired schoolboy into a confident young man.

As well as the other young stars of the film, Daniel Radcliffe, Emma Watson and Rupert Grint, he has worked alongside the cream of British acting talent, including Jim Broadbent, Michael Gambon, Emma Thompson, Helena Bonham Carter and Alan Rickman.

The final movie, Harry Potter And The Deathly Hallows – Part 2, brings an end not just to the Harry Potter franchise, but to Matthew’s formative years too.

For many of the fans who camped out overnight for this week’s star-studded London premiere of the film – and for those who will be queuing up for next week’s midnight screening on Bradford’s IMAX screen – the end of the Harry Potter movies signifies the end of their childhood.

Neville says the final days of filming were emotional. “After the official wrap, I felt sad as we looked around,” he says.

“I couldn’t imagine what my life would be like without it. I’ll miss the cast and the crew. We knew the day was coming when it’d all be over, but I tried not to think about it. I’ve grown up with these films, they’ve been a massive part of my life.”

Neville undergoes big changes in the movie, leading Dumbledore’s Army in Harry’s absence. Matthew relishes becoming a big-screen hero.

“I got to wield the Sword of Gryffindor!” he says. “Neville’s changed a lot. He was a shy lad, brought up by a grandmother who doubted his abilities, so he lacked self-esteem.

“Now he’s a reckless resistance fighter who wants to do the right thing. He’s become more heroic. He’s got heart, courage and loyalty. Standing up to Voldemort is his defining moment.

“When I get letters from kids saying that, like Neville, they had low self-esteem and my performance has helped them, that’s when this job is most rewarding.”

Matthew has revisited his Harry Potter books over the years. “I always reread whichever book we’re filming, to refresh my knowledge. It’s surreal to think I read them as a child, and now I’m Neville,” he says. One of the highlights of Matthew’s journey was hearing praise from JK Rowling.

“She told me I was doing a great job, which meant the world to me,” he says.

As a child, Matthew juggled filming commitments with studies at St Mary’s School in Menston. He even took his mock GCSEs at the film studio. While scenes were being filmed on set, he was in a side room with other young members of the cast, hunched over exam papers.

It was while he was a pupil at Scala School For Performing Arts in Horsforth, appearing in TV dramas such as Heartbeat, that Matthew got his break, after queuing all day at auditions for the first Harry Potter movie, in Leeds.

“I didn’t hear anything for months and gave up hope, then I was invited to London for a screen test with the director, Chris Columbus,” he says.

“These films are classics, I’m proud to be part of that. I’m a huge fan of the Star Wars trilogy and to think our films will be ranked alongside those in years to come is incredible.”

And of life after Harry Potter? “I want to do something serious and gritty,” says Matthew. Watch this space.

Harry Potter And The Deathly Hallows – Part 2 is in cinemas, including the IMAX screen at the National Media Museum, Bradford, next week. There will be a midnight screening at the IMAX on Thursday, July 14, then 24-hour screenings continuing until Friday, July 15. For tickets, ring 0844 8563797.