The Danish Girl tells the story of Einar Wegener, the first person to undergo gender-reassignment surgery, becoming Lili Elbe. Eddie Redmayne committed to the role several years ago, while he was making Les Miserables with director Tom Hooper. "The process of preparing for the film was a huge education for me," he says. "The whole story was new to me, and I found it to be a passionate and incredibly unique love story about the lives of two extraordinary women. It moved me profoundly."

Eddie plays Lili Elbe

The two women in the story are Lili and Gerda (played by Alicia Vikander), Einar's wife who supported Lili through various operations. "What was wonderful was there was so much source material," Redmayne says. "There were photographs of Lili and Gerda, but also the paintings by Gerda of Lili. Then you have Man Into Woman, a book that was published after Lili's death. And of course you also have contemporary trans experience and all the many women who I met in preparation."

After playing Stephen Hawking, Eddie is used to the mixture of praise and criticism that comes with portraying a real-life icon. "If you are given the privilege to play someone like Lili or Stephen, the fear and anticipation of scrutiny just galvanises you to educate yourself and work harder," he says. "Whether I'm successful at it or not, I don't know. But what I learned as a human being and the generosity of the trans community in my preparation for playing Lili was pretty overwhelming."

He's also been struck by the film's timing. "I feel like in this past year, with discussions about trans issues and what trans have been going through, and the mainstream media, it's an amazing time in some ways," he says. "What Caitlyn Jenner has been doing is great. Her transition is a very unique and specific one. She has used her status to highlight some of the serious problems that trans women and trans men have to go through. And I hope that in some ways our film continues the discussion, because us learning to be allies to the trans community is so important."

Watch the trailer for The Danish Girl here: