[Princess Margaret] was always trying to radicalize things.

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.

Marking the differences between them was really important. It just became second nature. When we were choosing pajamas or something, instantly you'd be able to spot: those are [princess] Margaret, those are [princess] Elizabeth. It became this sort of language, really, of the two sisters.

People are so much more fascinated by the royal family generally than in England.

I did a lot before [being cast] because I knew how important it would be for playing somebody real, or attempting to - to show the team [the role] was something I would be fascinated to do. I read a couple of biographies and I watched everything I could find [about princess Margaret].

It was always said you couldn't have two sisters less alike. In a way [princess] Elizabeth was always internalizing everything and [princess] Margaret was always externalizing everything, so that became the basis. The storyline becomes about these two sisters: they're fighting for their position or trying to establish their identity in the world alongside each other and in relation to this establishment which only those two were a part of.

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.