Matt Smith has explained the contrasts of character which make the Doctor so different to his one-off portrayal of Christopher Isherwood in Christopher and his Kind.

“It was nice to have a vast contrast between the two,” he revealed to BBC News. “Christopher Isherwood is quite straight and relativity still I suppose, and in a very particular period, but the Doctor is mad and flamboyant and from every period…”

The drama tells the story of the celebrated author who escapes the repressive English society and the suffocating relationship with his mother for the decadent and politically unstable world of 1930s Berlin. It airs tomorrow (Saturday) from 9:30pm on BBC Two.