FILM legend Sir Anthony Hopkins described shooting in Oxford as the 'most fun' he has ever had on set during his illustrious film career.

Last year Hollywood transformed the city as film crews were spotted around famous landmarks for the fifth Transformers instalment.

Ahead of the film's release this week, the screenwriter of Transformers:The Dark Knight, Art Marcum, said the 79-year-old actor had taken him aside in the city to tell him how much he was enjoying himself.

Mr Marcum added: "I got to work with him in Oxford and he took me aside and said it was one of the most fun times he'd had playing a role in years because he never gets to play comedy.

"Nobody writes comedy for him and he loves to do comedy.

"People think of him as the guy with the gravitas that comes in and lays it all out, and he was having a ball."

The Welsh icon plays Sir Edmund Burton, an astronomer and historian who knows about the history of the Transformers on Earth.

For fellow screenwriter Matt Holloway, recruiting Sir Anthony, was a dream come true.

He said: "It's kind of a funny story, as we were developing this story, we started to talk about a Sir Edmund Burton-type character, this sort of keeper of the law, an English Lord.

"Maybe he's sort of the last of his kind, the last keeper of the secrets."

Not only does the latest chapter in the franchise mark long-time director Michael Bay's final hurrah but also shatters core myths of the films.

He told fans earlier in the year: "I can safely say that there's never been a Transformers film with the huge visual scope and expansive mythology as this movie.

"It's bittersweet for me.

"With every Transformers film, I've said it would be my last.

"I see the 120 million fans around the world who see these movies, the huge theme park lines to the ride and the amazing Make-A-Wish kids that visit my sets, and it somehow keeps drawing me back but, this time might really be it. So I'm blowing this one out."

The big-budget blockbuster, which has proved a breeding ground for Hollywood stars such as Shia LaBeouf and Megan Fox since Paramount unveiled the first film inspired by the hit toys in 2007, is embarking on a new era.

This time, fans will learn more about characters who have not yet enjoyed the spotlight, including Sir Anthony's character Sir Edmund Burton.