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.

There's so much going on in Andrei [Bolkonsky]. He's wrangling with these big existential conundrums, and he tries out different routes to fulfillment. He tries falling in love, that doesn't work. He goes to war and searches for military glory, that doesn't work. He does the quiet life of a farmer. He's always active. That's what I loved about him, he's always looking, searching. He's really inquisitive.

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.

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

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.

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.

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