Being in Russia filming War & Peace...filming War & Peace alone is an extraordinary experience, but to be out there was just magical.

I'm quite a smiley guy, I have my moments, but I think I'm generally of a relatively optimistic nature.

The Russians were all really accommodating, and that made it really special. To be allowed in Catherine's Summer Palace...Lily [James] and I have this scene where we fall in love and we waltz up and down this enormous gold hall with thousands of candles and a live orchestra and 300 Russian extras. To do those scenes in situ really meant it was a once-in-a-lifetime job.

If you're constantly stepping outside of the character and judging them, you'll never really be able to fully engage because you'll always be slightly cynical.

Being in Russia filming War & Peace...filming War & Peace alone is an extraordinary experience, but to be out there was just magical.

Every day, every scene, you were like, "My god. I'm doing a scene with Brian Cox today and then I'm onto a scene with Stephen Rea." For us young actors, I think we were all very, very star-struck and impressed by the caliber of everyone who came out.

You really try to work the character out and spend time in the headspace of the character. That's what I did.