Heavyweight role for actor Stevens
Dan Stevens has revealed the biggest challenge of filming his role as Lancelot in Night At The Museum: Secret Of The Tomb - the heavy armour gave him a bad back.
The former Downton Abbey star joined the cast for the third museum film starring as a Knight of the Round Table helping the regular characters on their quest to save the magic of the Tablet of Ahkmenrah.
Dan said he was excited about his costume for the role - before realising it weighed 50lb.
"When I first tried it on, it was like a dream come true for me. But after four months of filming, I think I'm a couple of inches shorter than when I started."
He added: "I hadn't quite appreciated that when taking the role on. I had a very bad back by the end."
It marks Dan's return to comedy for the first time since he trod the boards as a member of the Cambridge Footlights sketch troupe as a student - and he said he was "delighted" to try his hand at some humour again, rather than the costume drama for which he is known.
The latest Night At the Museum film stars the late Robin Williams as Theodore Roosevelt.
Speaking at a press conference in London to launch the film, co-star Ben Stiller paid tribute to Robin, to whom the film is dedicated, saying: "Every time we got to work together on this movie franchise I was always excited, and he was very generous and kind, and would make everyone feel as if they were an equal.
"So I feel really lucky to have had that time with him and to be in the movies with him. And it's great that the movies exist, but for me it's the experience that I'll always take away."
Robin Williams committed suicide in August.
:: Night At The Museum: Secret Of The Tomb will be released in UK cinemas on Friday.