Helen Mirren is one of those terrifying British actresses whose competence is almost ferocious. She's built to play women of power and intelligence. But when it came to her sovereign, the biggest big dog in the female power kennel (sorry, Oprah), Mirren, 61, was the one intimidated. Worse still, in The Queen, which imagines the royal-family dynamics and political maneuverings after Princess Diana's death, she has to play two Elizabeths: the public one, whom everybody feels they already know, and the private, whom few have seen. "I was incredibly nervous," says Mirren. "I didn't want my performance to be clever but thin, and I didn't want it to be a satirical impersonation." (There have been enough of those.) What finally helped her, she says, was looking at paintings of the monarch and concluding that she was going to do her own portrait-- "my intellectual deconstruction of her." From there it was all about research, the voice and the bearing. The public persona came first. "As I watched her, I saw that although she has an extremely composed exterior, there's an incredible beat of energy within," says the actress. The private queen--mother, wife and grandmother--is where Mirren really gives the old girl a heart--a proper duty-bound, selfless one. Her queen is not cold and distant. She's just not programmed to display her feelings. Says Mirren: "To her, it would simply be rude to impose your emotions on others."