Angelina Jolie said she has always been drawn towards villains rather than princesses, ahead of her latest role as Sleeping Beauty sorceress Maleficent.
The 38-year-old makes her big-screen comeback in the title role in the Disney film of the same name, four years since action thrillers Salt and The Tourist, as she has been focused on directing.
The Oscar-winning actress, wearing a black beaded billowy dress by Versace, was joined on the rain-sodden blue carpet by fiance Brad Pitt and their eldest son Maddox at the preview of a special costume exhibition at London's Kensington Palace.
"What isn't there to like about Maleficent? She was my favourite when I was little. I wasn't into princesses and I thought she was so elegant and so powerful," she said.
"She scared me a little bit, but I think it's a natural thing for children, and everybody to want to understand their fears and to get closer to those things - the shadows, the dark and what frightens us - so I was always curious."
Jolie continued: "And then I read the script. It's such a beautiful script. It was very moving and it helps you understand that things are not black and white.
"There isn't just good and evil in the world, and she's an advocate of that. She wasn't always the way that she is now."
The mother of six, whose five-year-old daughter Vivienne makes her acting debut in the film, said she understands why fairy tales have such universal appeal.
"I suppose we all want to believe in happy endings," she continued. "But fairytales take aspects of the human condition and magnify them, the characters and feelings. They help us relate to the questions and stories but they do it in a much more colourful way."
Elle Fanning portrays Princess Aurora, with British actor Sam Riley as Maleficent's henchman Diaval.
"Whenever anyone asked me what I wanted to be when I grew up, I would say a Disney princess. I was like five (years old). That was the ultimate dream," Fanning said.
The 16-year-old, who epitomised the princess look with a cream embroidered gown by Georges Hobeika, added: "It was a huge spectacle - and when you add Angelina to the mix - so I was in awe the whole time."
Riley, 34, added: "I said yes because I had never done anything like this before and to work with Angelina on a big movie like this, I thought I'd be an idiot to say no. I really loved it because it's different from what I've done previously - incredible sets and movie stars. It's fun."
The Maleficent Costume Display features costumes and props from the film, including the Maleficent wings.
Maleficent, which also stars Lesley Manville, Juno Temple, Imelda Staunton and Sharlto Copley, opens in cinemas on May 28.