The 73-year-old actor, who is battling prostate cancer for seven years, reprised his role as Gandalf the wizard from Peter Jackson's award-winning 'Lord of the Rings' trilogy in the prequel film, reported Femalefirst. "It was like going back home, really.

It was more of the same, which is what was required, but it wasn't boring. I mean, a whole new set of circumstances and a new Bilbo (Baggins) to play with in Martin Freeman, and all those 13 dwarves, and a new aspect of the story," he said. The film had a royal premiere yesterday and was attended by Prince William.

Sir Ian McKellen as Gandalf