After starring in dramas like Little Dorrit and Upstairs Downstairs Claire Foy was earmarked for stardom by trend bible Vogue. She went on to star in a Hollywood blockbuster with Nicolas Cage, Season of the Witch. But it was her role in Peter Kosminsky's drama The Promise, that made the biggest impact on Foy.
She plays Erin, an 18-year-old visiting Israel for the first time. She's following in the footsteps of her grandfather Len, a soldier in the British army in Palestine during the Mandate period who kept a diary of his turbulent time there.
It's a powerful tale of love, war and betrayal, telling the stories of both Erin and Len - two young people caught up in the same struggle more than 60 years apart.
Here, Foy reveals her passion for the project, and explains why she'd like to burn every costume she's ever worn.
What was it that drew you to The Promise?
I remember the very first audition very clearly. I got sent 25 scenes, and was asked to prepare all of them, which is what Peter does, God love him. It was so much work.
I remember reading a scene, and I had no idea what it was about. But then when I got the finished script, I couldn't stop reading it. It was just the most amazing story.
Peter is just so talented, it's unbelievable. Anyone who watches it will be blown away by the story. He somehow makes a political piece that's so emotionally driven by the characters. There's no agenda in it. It's just amazing, it's my favourite job ever, and I think it always will be.
That's quite a statement.
It's the whole reason I want to act. Obviously I couldn't do a job like this every week - it's such undertaking and it requires a lot. But I loved it; it's about something bigger than just the drama. And I loved the character so much. There was so much in her.
She's not exactly a sympathetic character, is she?
No, she's not very nice at all. [Laughs] She's quite unforgiving and a bit bolshy, a bit sarky, and a bit of a cow, really. But I think it works because she's a real person. And I felt very strongly that when I was 18 I was a lot like Erin. I was quite mouthy, and sticking up for things I didn't really believe in because I didn't know anything about the world. She's a difficult character to love, but she's real.
Erin suffers from epilepsy as well. Did you do any specific research into that subject?
Yes. I had to. I had to have a few fits on film, so I had to be quite technically specific about them, because some of the people watching will be epileptic, and there's a duty to get it right.
We had some people from the Epilepsy Foundation come in and talk to us and give is some information about it. And there are things you can watch on YouTube about it as well. I watched some fits, but it felt a bit weird to be watching them. It seems like such a personal thing. And I watched quite a few documentaries with people talking about what it felt like to have epilepsy, and how it affects your life. I think she's so aggressive all the time because she doesn't want people to think that she's got a disorder or needs help. She doesn't want to be patronised at all.
Did you do any other research into the situation in Israel?
Yes. I really shouldn't have done, because Erin was a complete innocent about the whole thing and really naïve about it, but once I'd read the script I had to keep reading, because it opened a completely new world to me.
I got the job months and months before we started shooting, and I actually became a member of the British Library - which is very nice - and I went and found a book about a man who had written a diary of when he was in Palestine at the same time that the character of Len was there. So it helped me no end.
The series was filmed in Israel. Had you been there before?
No, never. And I probably never would have been but for this. For a country that's so aware of its politics it was brilliant they gave us permission, because we couldn't have done it anywhere else.
What did you make of it?
That's such a tricky one. I don't know really. It's a beautiful country, it's warm, it's got lovely food, Tel Aviv's an amazing city, it's a really nice place to film. It's a very metropolitan place, with a relatively European feel to it.
Politically, it's not my favourite place in the world. I'd never been anywhere before that was in conflict, and I very much felt that it was in conflict.
Did you see daily reminders of that?
I did, yes. We were staying next to the US Embassy in Tel Aviv. The level of security is just astonishing if you're not used to it. There are people walking around withy guns, and there are massive army helicopters everywhere, and fighter jets going past your hotel window. You don't get that everyday back here. And the weird thing for me was you knew they were going somewhere. They weren't just off on an exercise.
Were there any problems with people who didn't want you there?
I think it was more difficult for us than it was for the actors in the 1940s scenes, because they were all in period costumes and period transport. But when we turned up in Arab areas and put an Israeli army roadblock in the middle of their city, people didn't know we were actors.
It was particularly difficult for the guys dressed up as IDF soldiers. They had people coming up to them swearing.
So many people were so welcoming, and so pleased that we were making the drama,and filming in their country. But certain people I guess felt like 'you're coming over here to tell this story, you don't know anything about it.' That's just human nature.
You're known for Little Dorrit, Upstairs Downstairs, and you've got a film coming out with Nicolas Cage, Season of the Witch, set in medieval times. Was it nice to be making a drama where you were wearing contemporary clothes?
Oh yes! It really was. Costumes are costumes, to be honest, and by the end of anything, you hate them. I always hate them. I want to burn them all when I'm finished with them, I hate them all so much. You end up being really uncomfortable, really hot or really cold, the shoes don't fit. As much as the costume department are wonderful, there's only so much they can do.
But in this I got to wear Converse, which was a massive plus. But I'm so thrilled to have done a modern piece. So much stuff is period, and I couldn't believe my luck to play such an amazing character, and for it to be set in the now. And it has to be good for me that casting people will see me not in a corset for once!
You've talked about how much you loved making it, but where does The Promise sit in terms of how proud you are of the piece?
I really hope people watch it, and I really hope they like it, and I hope people don't get bogged down by the politics, I hope people just watch it for the wonderful story that Peter has crafted.
Little Dorrit will always be so important to me - it was my first big job, it was a character I got to play for six months. So that and this, for different reasons, have to come out top.
I felt so emotionally attached to Erin and so believed her story, and I loved working with Peter so much. I think every job will be different, but I think for me, creatively, and of the jobs I'll be proud to show people, this is definitely up there at number one. It's got so much integrity. All actors want to do something that's good - something that's pure and has no vanity, something they can be really proud of. Well, for me, this was that job. I'll be so lucky to ever do a job that I love this much again.