The Danish Girl tells the story of Einar Wegener, the first person to undergo gender reassignment surgery, becoming Lili Elbe.
"The process of preparing for the film was a huge education for me. 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," he said. (Also Read: Eddie Redmayne's 'Brilliant Education' From the Transgender Community)
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," Mr Redmayne said.
"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," Mr Redmayne added.