I started to really enjoy the fact that [princess] Margaret was an exhibitionist. Even on a day-to-day basis, Margaret's costumes were always so much more dramatic and bold than Elizabeth's were.

I still get stage fright horribly. I still get nervous. I do tend to find when you're playing characters, often - just for the time you're playing them - there are sides of your personality that get stronger because you draw on them more.

My dad is a big extrovert - he's a doctor - but he always loved [William] Shakespeare and he took us to tons of theater.

I started to really enjoy the fact that [princess] Margaret was an exhibitionist. Even on a day-to-day basis, Margaret's costumes were always so much more dramatic and bold than Elizabeth's were.

At the same time, [princess Margaret] had a fragility and an insecurity in who she was and her position, because her sister had always got the education ever since David [Edward VIII] abdicated.

Everybody has an image of [princess Margaret], to a certain extent. But I felt it would have been harder if we were playing them as they are now. In a way, I don't know how much of a living memory we as a collective have of them in the '50s, when Margaret was 21 and this sort of Elizabeth Taylor. You don't think of your grandparents as being teenagers. You just can't - your brain just can't go there!

That's exactly how I felt. So getting to suddenly know this young [princess] Margaret, who had this extraordinary life - it was sad and tragic and difficult and sort of astonishing and getting to know her young self was amazing because it completely defied all my expectations.